in time for Christmas all these gifts must be mailed immediately A. So as to be receivedB

问题补充：

in time for Christmas，all these gifts must be mailed immediately

A. So as to be received

B. In order to receive

C. So as to be receiving

D. In order to be received

答案：

A. So as to be received

B. In order to receive

C. So as to be receiving

(答案→)D. In order to be received

解析：考查不定式短语做状语。固定短语in order to do sth为了做某事；该句型可以放在句首，而so as to…是不能放在句首的。句意：为了在圣诞节的时候及时被收到，所有的礼物都要立刻被邮寄出去。故D正确。