出票不在当天的订单，不可以预定次日（）之前起飞的航班。

Have you checked all the CDs _____ to the mountainous area next week?

A．sent

B．to be sent

C．sending

D．being sent

The little boy was so careless with his spelling that she often_____ letters from words.

A．left out

B．left behind

C．left off

D．let alone

空段清扫器用以清扫（）非工作面的（）。

平均出车时间指什么？

"四个不予登记"的具体内容是什么？