In order to be for Christmas, all these gifts must be mailed immediately.
A. in time
B. at one time
C. at a time
D. in no time
网友回答
(答案→)A. in time
B. at one time
C. at a time
D. in no time
解析：考查介词短语辨析。A及时；B以前，曾经；C一次，每次；D立刻，马上；句意：为了能够及时赶上圣诞节，所有的礼物必须立刻被邮寄。根据句意说明A正确。