Children are to meet with setbacks (挫折) as they grow up, so their parents don’t have to worry about it.
A. possible
B. due
C. necessary
D. bound
网友回答
A. possible
B. due
C. necessary
(答案→)D. bound
解析：考查形容词辨析。句意“孩子在成长的构成中肯定会遇到挫折，因此他们的父母不必担心。”A“可能的”；B“到期的，应得的”；C“必需的”；D“有义务的，受约束的”。be bound to do sth.“一定会做某事”。故选D。