顺序练习
话题练习
题型练习
口语评分
写作评分
阅读机考
听力机考
口语机考
A.
They deal with information on a wide variety of academic topics.
B.
They often have to go to professors’offices to help.
C.
They work at times of their own choosing.
D.
They come from many different parts of the world.
正确答案:AC
译文