—Where are Lucy and Lily?—Oh the two girls must a game in the garden now.A. playB. are

问题补充：

—Where are Lucy and Lily?

—Oh , the two girls must a game in the garden now.

A. play

B. are playing

C. played

D. be playing

答案：

A. play

B. are playing

C. played

(答案→)D. be playing

解析：此题重点考查情态动词的用法，must为情态动词，后跟动词原形故排除B、C；根据语境：“---露西和莉莉在哪儿？”由now可知表示动作正在进行,故选D