题干
Everyone makes mistakes in life．The key is not to repeat ________ again．
A：it
B：this
C：that
D：them
答案(点此获取答案解析）
D
Everyone makes mistakes in life．The key is not to repeat ________ again．
A：it
B：this
C：that
D：them
④处欣赏时间较短的原因可能是 （ ）