首页 > 留学知识库

问题: 难题

Look up!____you____the clouds moving slowly in the sky?
A. do, see B. have seen

解答:

A. do see.

就是现在让看,问的看没看见,当然用现在时.

如果不是look up, 是其他词,比如Hurry up.就是问"你没看见.."?可能会用完成时.