问题补充：
It is suggested that all these gifts be mailed immediately in time for Christmas.
A. in order to have received
B. so as to receive
C. so as to be received
D. so as to be receiving
答案：
A. in order to have received
B. so as to receive
(答案→)C. so as to be received
D. so as to be receiving
解析：句意：大家建议所有的礼物要立刻被邮寄为了能够在圣诞节的时候及时的被收到。In order to和so as to do都是表示目的状语，gift和receive是被动关系，用不定式的被动式，所以选C。
