Some  people think that all university students should study whatever they like .Others believe that they should only be allowed to study subject that will be useful  in the future, such as those related to science and technology .Relieved from the overloaded burden of homework in senir high school ,many students go into college only to find that they have plunged into the sea of knowledge without anybody telling  them where to swim .

Some people are filled with misgivings about university students' choices :how could they possibly tell ,at such a young age ,which subject is more useful than others and choose it as their focus of study in the next four years which are probably the  most valuable time in their entire life .In my view ,however ,such consideration seem rather superfluous ,for choosing a subject by students themselves is beneficial to the students and the whole society as well . 

Firstly ,as the saying aptly express ,"interest is the best teacher ,"which means onl when we have passion for something can we do it better . A good teacher must love teaching and keep the students' benefit in mind ,and a physician must love life-saving before he can humane and sympathetic towards his patients ,while a pianist should be crazy zbout playing and then become a top-notch artist .Contrarily , a person not fasinated by what he is doing is much less to get anywhere in his career .

Secondly ,the boundry between "useful " and "useless " subjects is not that clean-cut as many people might have expected . Undoubtedly , science and technology are of paramount importance to the development of our world ,but it's does not follow that other less practical subject like philosophy and literature are useless .while the incresed knowleddge of our body ,for example ,may help us live longer ,a better understanding about history ,culture and ourselves enable us by liberal arts may show us what kind of life  is more valuable and therefore more worth living .

To  conclude ,rather than restricting the students to certain "useful " subject , parents and universities should encourage them to study wahtever they like to .By doing so ,students will be able to learn those things ,be it useful or not ,that really interest them ,and this is helpful to the future career of the students ,and to the contribution they can make to the world .