We are supposed the lost child at once.A. findB. to findingC. findingD. to find

问题补充：

We are supposed the lost child at once.

A. find

B. to finding

C. finding

D. to find

答案：

A. find

B. to finding

C. finding

(答案→)D. to find

解析： be supposed to do sth应该, 认为必须, 被期望做某事.根据题意我们被期望立即找到失踪的孩子.所以选D.