一、流利阅读
例句
More than 50 years after it jumped the species barrier and became one of the most devastating viruses to affect mankind.
单词
species 种类、种族
barrier 屏障、障碍
adversary 敌手、对手
例句
More than 50 years after it jumped the species barrier and became one of the most devastating viruses to affect mankind.
单词
species 种类、种族
barrier 屏障、障碍
adversary 敌手、对手