There are some police cars in front. What do you suppose ?
A. is the matter
B. is happened
C. is the wrong
D. the trouble is
网友回答
(答案→)A. is the matter
B. is happened
C. is the wrong
D. the trouble is
解析：do you suppose是插入语。另：Can you tell me what is the trouble?虽然是宾语从句但还是要用what is the trouble而不是what the matter is.