题干
______some people are motivated by a need for success, others are motivated by a fear of failure.
A：Because
B：If
C：Unless
D：While
答案(点此获取答案解析）
D
______some people are motivated by a need for success, others are motivated by a fear of failure.
A：Because
B：If
C：Unless
D：While
( )
是具有
