从15个人中取5个人，且有3个人不能都取，问有多少种取法
参考答案：[*]
Lizzie was______ to see her friend off at the airport.
A a little more than sad B more than a little sad
C sad more than a little D a little more than sad
对绞车房的接地装置多长时间进行一次检查？
