Day4-5

1、lead weight

a weight made of lead

The cars carry lead weights for ballast.

Her heart felt like a lead weight inside her chest.

2、elliptical

The word elliptical is derived from the oval shape known as an ellipse. Many comets have an elliptical orbit around the Sun that brings them closer at some times and farther away at others.

adj characterized by extreme economy of expression or omission of superfluous elements

“"the explanation was concise, even elliptical to the verge of obscurity"- H.O.Taylor”

3、spiral

A spiral is a coil or curl, like the shape of a piece of hair wound around your finger, a Slinky toy, or a corkscrew.

A curve forming a series of circles that become gradually larger or smaller is one kind of spiral. You can also use the word as a verb when something moves in a spiral shape: "Then the wind died and I watched my kite spiral down to the ground." The origin of spiral is the Medieval Latin spiralis, which means "winding or coiling," from a Greek root: speira, "coil, twist, or wreath."

“The path spirals up the mountain”

“Metro地铁 is effectively in the middle of a death spiral,” Moneme said.

But consider the recent statement by Aetna’s CEO that ObamaCare is entering a “death spiral” as higher premiums保险 drive healthier customers from the marketplace.

4、track

If you document your study time and record all your exam scores, then you track your progress in school. In this case the verb track shows that you're following the path of something. The noun track can refer to a path of a more literal kind.

The noun track can describe a variety of paths, such as the rails that trains chug along, a course that racehorses run, or the big oval course in an ice rink. If you're competing in a five-lap race and you have the fastest speed after the first four laps, you're on track to win the race. In this case the term "on track" is describing a figurative path, one that indicates you're in a good position to achieve what you want

“the track of an animal”

“track mud into the house”

“the title track of the album”

5、irrational

If you're a straight-A student and still you worry about failing all of your classes, you're being irrational. Your fears are not based on fact and not likely to come true.

6、bishop

A bishop is a religious authority figure in some Christian churches. In many churches, a bishop ordains, or appoints, ministers and priests.

7、refute

The verb refute is to prove that something is wrong. When the kids you're babysitting swear they brushed their teeth, you can refute their claim by presenting the dry toothbrushes.

Evidence and arguments are used to refute something. So are facts. For example, if children who eat chocolate before going to bed go straight to sleep, that refutes the idea that sugar keeps them up. Refute comes from the Latin refutare for "to check, suppress." A near synonym is confute, but save refute as an everyday word for proving something is false.

rebut / refute

To rebut is to try to prove something isn’t true, but to refute is to actually prove it isn’t. Getting them mixed up won’t get you kicked out of the debate club, but it’s worth knowing the difference.

“The speaker refuted his opponent's arguments”

After Trump signed the original order, Iraqi Prime Minister Haider al-Abadi refuted the ban and said he would consider reciprocal相应的 measures.

8、astronomer

A scientist who studies the objects in the sky, including planets, galaxies, black holes, and stars, is called an astronomer.

These days, the terms astronomer and astrophysicist are used interchangeably, to talk about any physicist who specializes in celestial bodies天体 and the forces that affect them. Astronomers use telescopes and cameras to observe the stars and other objects in the sky, and they often use complicated math to make predictions and solve puzzles about their movements and locations. The Greek root, astronomia, literally means "star arrangement."

9、ripple

A ripple is a small wave on the surface of something, such as a ripple that forms a ring around the spot where you threw a pebble into the pond.

Ripple can also be a verb. For example, you might see raindrops ripple on top of a puddle水坑. Ripple was first used in the 1670s to describe something that causes a ruffled波浪，皱褶 surface, sort of like how water seems to momentarily gain texture质感 as it's stirred. Ripple later came to describe a very small wave, but you've probably heard of the "ripple effect" in which tiny waves spread, setting off more and more waves.

nother set of sensors probed探索，how seismic 地震的signals ripple through East Coast rock layers.

10、crest

A crest is a showy花哨的 tuft一丛 of feathers on the head of a bird. It's easy to identify a male cardinal by its bright red color and the tufted crest on its head.

The Latin word crista, which crest comes from, means "tuft or comb."An animal's crest can be feathers, fur, skin, or a comb like a rooster's. Something that resembles such a feature can also be called a crest, such as a plume翎，羽毛 on an old-fashioned helmet. The top or highest part of something is also a crest, like the crest of a hill or the crest of a wave. As a verb, crest means "to reach the top" like when you crest a mountain.

the top or extreme point of something (usually a mountain or hill)

the top line of a hill, mountain, or wave

reach a high point

“The river crested last night”

11、infrared

having or employing wavelengths longer than light but shorter than radio waves; lying outside the visible spectrum at its red end

“infrared红外线的 radiation”

“infrared photography”

12、ultraviolet

Use the adjective ultraviolet to describe light with a wavelength that's less than visible light, but longer than x-rays. You can't see ultraviolet light.

You might hear people talk about ultraviolet light as UV radiation — it's the part of sunlight that can give you a sunburn if you're exposed to it for too long. In physics, this kind of electromagnetic radiation is defined by how long its waves are. The word itself, ultraviolet, refers to the fact that its wavelength is shorter than the violet end of the spectrum of visible light. The Latin prefix ultra means "beyond."紫外线

“ultraviolet radiation”

“an ultraviolet lamp”

In a separate online forum论坛, the authors discussed ways to lower risks, like installing germicidal杀菌的 ultraviolet lights or tracking and isolating dangerous “superspreader” patients.

13、contract

When you and someone else have agreed on something and that agreement is both binding and enforceable by law, you have a contract. When you rent an apartment, you and your future landlord sign a rental contract.

14、hitherto

Use the adverb hitherto when you're describing a state or circumstance that existed up until now. If you find a hitherto undiscovered hidden tunnel in your cellar, you're the first to discover it.

When some particular situation has existed so far, up until the moment that you're speaking of, you can use the word hitherto迄今 to talk about it. You could say that you're taking a hot air balloon ride that you were hitherto too scared to contemplate沉思, or that a very shy girl in your philosophy class who was hitherto totally silent finally spoke up today and asked a very intelligent question.

15、intrinsic

The intrinsic qualities of something have to do with its nature. An intrinsic quality of dogs is that they're loyal.

Anything intrinsic comes from within. Doing a job for only money is not intrinsic. Doing a job because you love it is intrinsic; the motivation comes from within. It's good to treat people as having intrinsic value. If you like someone for intrinsic reasons, then you have no other motivation. The opposite of intrinsic is extrinsic, for things that come from the outside instead of from the inside.

“"form was treated as something intrinsic, as the very essence of the thing"- John Dewey”

But it focuses instead on the ingredients and their intrinsic tastes rather than revolutionary techniques, like the foams泡沫，海绵 and spheres that distinguished El Bulli.

16、cesinum clock

an atomic clock based on the energy difference between two states of the caesium nucleus in a magnetic field

17、platinum

Platinum is a chemical element that's a heavy, precious metal. If you want a really fancy wedding band, go for platinum.铂

18、latitude纬度 longitude经度

In geography, longitude refers to the imaginary lines that bisect the globe through the North and South Poles (the ones that run vertically, as opposed to the lines of latitude that run horizontally, parallel to the equator).

Use the word latitude to describe how much freedom you have in making choices. For example, if a teacher gives you latitude in writing your paper, you might get to choose the topic and how many sources to include.

Latitude is related to the Latin word latitudo, meaning "breadth, width, extent, size." You might already know that latitude is used to indicate the distance an object is from the equator, measured from north to south. Latitude can also be used to mean "be given the space to act and decide for oneself," like the latitude parents might give responsible kids.

“allowed his children considerable latitude in how they spent their money”

20、geodesic

of or relating to or determined by geodesy地测学

(mathematics) the shortest line between two points on a mathematically defined surface (as a straight line on a plane or an arc of a great circle on a sphere)

“Initially, glass planes with carbon fiber frames to build geodesic domes on the surface, plus a lot of miner/tunneling droids,”

Day2

21、hail

Hail is when chunks of ice fall from the sky. Also, to hail someone is to greet them or say good things about them. Or it can be a way to tell people of your homeland, as in: "I hail from the Moon."

If twenty third-graders all sent spit-balls up in the air at once, the spit-balls would then hail down on the class. If a presidential candidate has an idea for fixing the nation's woes, many people will hail that idea as the next great panacea. If you see your former prom date walking down the street, you may want to hail him to say hello or, perhaps, you will want to hail a cab and get out of there as fast as you can.

hale / hail

Hale describes someone hearty and healthy. Rarr. All hail the next word! To hail is to greet enthusiastically. And when it hails, ice falls from the sky and hits those hale people on the head.

At the train station, she was directed to hail a “black taxi cab.”

In an introductory note, Kremer hails Weinberg as a “great composer . . . a personality with an impressive and obvious ‘signature.’ ”

22、ionic

containing or involving or occurring in the form of ions

“ionic charge”

“ionic crystals”

“ionic hydrogen”

Separators also inhibit抑制 dendrites树突, while offering minimal resistance阻力 to ionic transport.

23、paradox

Here's a mind-bender: "This statement is false." If you think it's true, then it must be false, but if you think it's false, it must be true. Now, that's a paradox!

One of the surprising paradoxes of Trump’s stunning political rise is that the former reality television star hasn’t always succeeded on the biggest stages.

24、arena

If you're watching a college basketball game in person, chances are you're in an arena — a building specially designed for sporting events and large-scale rock concerts.

There's not much difference between an arena and a stadium, although an arena is enclosed and a stadium sometimes has an open roof. Football is usually played in a stadium, while basketball and other sports typically hold their games in arenas. The word arena originally meant "place of combat," and it's sometimes still used this way. Its root is harena, a kind of sand that was supposedly used on the floor during ancient Roman battles to soak up spilled blood.

the central area of an ancient Roman amphitheater where contests and spectacles were held; especially an area that was strewn with sand

a particular environment or walk of life

Synonyms:area, domain, field, orbit, sphere

Types:show 10 types...

Type of:environment

the totality of surrounding conditions

South Plains plays its home games at the Texan Dome, a 3,300-seat arena that features championship rodeo banners and sometimes leaks in rainy weather.

Governance and government rely increasingly on a science that is embedded in socio-political arenas populated by scientists, policymakers and citizens, among others.

NatureJan 17, 2017

Beyond these compelling numbers, there are lessons to be learned in the political arena.

The New YorkerDec 29, 2016

The scientists then trained the animals to feed from a bowl in a test arena.

25、repell

动词.排斥，相斥，击退，驱逐

网络.使厌恶，拒绝，抵制

repellment

Use the verb repel when you want to turn something away. You might drench yourself in bug spray to repel the mosquitoes that plague you when you go camping.

This versatile word can be used in relation to everything from bugs to unwanted romantic advances. The word repel can be used to describe the act of driving something away, as in the case of bugs or other pesky critters, including potential suitors. It can also be used to describe something that causes disgust or distaste. For example, the thought of eating snails might repel you.

“repel the attacker”

How can you tell that something is repellent? You dislike it so much, you want nothing to do with it. If something is repellent, it is highly offensive or disgusting.

Experts warn that some repellents are not formally tested and that using them may offer swimmers and surfers a false sense of protection.

New York TimesJan 18, 2017

“Our community is founded on principles of respect for all views, even those that we personally find repellent,” Hexter said in statement after the cancellation.

26、curvature

the property possessed by the curving of a line or surface

the rate of change (at a point) of the angle between a curve and a tangent to the curve

Type of:

derivative, derived function, differential, differential coefficient, first derivative

the result of mathematical differentiation; the instantaneous change of one quantity relative to another; df(x)/dx

n (medicine) a curving or bending; often abnormal

“curvature of the spine”

27、warped变形弯曲

used especially of timbers or boards; bent out of shape usually by moisture

“the floors were warped and cracked”

But she says there's another possibility that emerges from the way the orbital plane of the solar system is warped beyond Pluto冥王星.

As slavery twisted politics and society in Alabama and throughout the South, it also warped the state’s finances.

28、elongated

Something that's elongated is stretched out, or extended so that it's longer than usual. Some painters, like El Greco, are known for their strange, elongated figures.

Things can be elongated because they're literally pulled and stretched, while others are described this way because they are very long and thin to start with. A young woman's elongated neck or your tall, skinny dad's elongated body are both examples of this. The Latin root is elongare, "to prolong or protract," from longus, or "long."

drawn out or made longer spatially

“Picasso's elongated Don Quixote”

having notably more length than width; being long and slender

“the old man's gaunt and elongated frame”

The message of this elongated award season is: “See this movie or be left adrift in the cultural conversation motion pictures gratefully provide.”

Los Angeles TimesFeb 25, 2017

“People are asked a question, and they preface their answer with an elongated ‘soooo.

New York TimesFeb 24, 2017

The holes form half-moon slivers, squares and elongated triangles, each several feet deep and lined with neon tubing.