A．If he has a pet companion.
B．If he has less stress of work.
C．If he often does mental calculation.
D．If he is taken care of by his family.

A.If
B.
B．If
C.
C．If
D.
D．If
E.


【参考答案】

A
解析：选项均以If he开头以及其中的less stress of work，is taken care o......

(↓↓↓ 点击下方‘点击查看答案’看完整答案 ↓↓↓)