—What class are you in?—I’m in ____, ____.
Without enough trees, soil won’t be kept____. And then sandstorms may happen.
The United Nations has done a lot for the peace of the world since it was in 1945.
He teaches ______ English there.
We shouldn’t use plastic bags. We should take our own bags ___.And we also should walk ___driving to the supermarket.
Our teacher has chosen some students as volunteers, Mary, Sally and me.