脂质体的特性不包括（）
A.靶向性
B.缓释性
C.放置很稳定
D.降低药物毒性
E.提高药物稳定性
参考答案：C
—We are worried about Tom. Why hasn’t he come back?
—Don’t worry. He ______ in a traffic jam.
A．might be caught
B．may have been caught
C．can have been caught
D．should have been caught
The letter from his parents was short. There wasn’t news.[ ]
A. many
B. a few
C. much
D. few
