What ______ Mary _______?(do) She ______ (look) at a picture.
问题描述：
What ______ Mary _______?(do) She ______ (look) at a picture.
答
What ___is___ Mary ____doing___?(do) She ____is looking__ (look) at a picture.
该题考察的是现在进行时，Mary是第三人称单数，所以be动词用is
答
what are Mary doing ? She is looking at a picture .
答
What is Mary doing?She is looking at a picture.
意思是，Mary正在做什么？她正在看一张图片（或照片）。
答
is doing
is looking
答
is,doing,is looking