问题补充:
Teenagers should learn to protect from all kinds of danger.
A. them
B. they
C. their
D. themselves
答案:
A. them
B. they
C. their
(答案→)D. themselves
解析:考查代词辨析。them意为“他们”,作宾格;they意为“他们”,作主格;their意为“他们的”,作形容词性物主代词,后面跟名词;themselves意为“他们自己”,作反身代词。句意为“青少年应该学会保护自己免受各种危险。”protect oneself意为“保护自己”。故选D。