The boys are making model planes over there.(对画线部分提问)

问题描述:

The boys are making model planes over there.(对画线部分提问)
The boys are making model planes over there.(对画线部分提问) _____ the boys _____ over there?
画线的是are making model planes
不要说前面少了条线,要画线的是 making model planes 才能问 What are the boys doing over there?现在多画了个are.我就不会了.

What're the boys doing over there ?