问题补充：
—Hi, Mary. ?
—Not so well. I can’t keep up with the other students.
A. How long have you studied chemistry
B. Who is teaching you chemistry
C. How is your chemistry study going
D. Where are you learning chemistry
答案：
A. How long have you studied chemistry
B. Who is teaching you chemistry
(答案→)C. How is your chemistry study going
D. Where are you learning chemistry
解析：How long have you studied chemistry你学化学多久了?Who is teaching you chemistry谁叫你化学?How is your chemistry study going你的化学研究怎么样?Where are you learning chemistry你在哪儿学习化学?根据下文,不太好,我不能跟上其他同学.结合语境可知选C.
