--- Look! Everything here is under construction.
--- What’s the pretty small house that for?
A. is building
B. is being built
C. is built
D. had been built
网友回答
A. is building
(答案→)B. is being built
C. is built
D. had been built
解析：句意：上文，看！这里的每一件事都正在修建中。下文，正在被修建的这个漂亮的小房子是干嘛用的？“房子是正在被修建”，故用现在进行时的被动语态，选B。