Question

Mr .and Mrs.Brown()their son all the night because they didn't find him

A are worried about B worry about C worries about D were worried about

Answer 1

Mr. and Mrs. Brown were worried about their son all the night....

answer: D
理由：1. be worried about sth. ＝ worry about是个词组固定用法
2. 时态是过去时 所以正确答案要么是 were worried about sth. 要么是 worried about sth. 后者没有 所以正确答案是 D

Answer 2

选C
worried about 过去时, worry本身就是动词,无需be

Answer 3

B, worry 可以以主动态表达， 排除A,D, 有两个人就不是单数， 排除C

Answer 4

D。。。。。。。。。。。。。。