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
A. to be sent
B. to send
C. being sent
D. sending
解析：此处be supposed to do sth．意为“被期望做某事；应该做某事”，不定式做宾语。表示“消息被传送”，应该用不定式的被动式。注意：下列动词常跟不定式做宾语：want，wish，hope，expect，ask，demand，pretend，care，decide，happen，offer，refuse，fail，plan，prepare，order，cause，afford，beg，manage，agree，promise等。