The message is very important, so it is supposed as soon as possible.
A. to be sent
B. to send
C. being sent
D. sending
网友回答
(答案→)A. to be sent
B. to send
C. being sent
D. sending
解析：考察固定结构和语态。Be supposed to do sth应该做某事；根据句意可知使用被动语态。句意：那个消息非常重要，所以它应该尽快被发送。