Is Mr. Wang good at drawing his students into______ discussion?

Once we discover to crefor economicdevelopment.

You know, Bob is a little slow _____ understanding, so…— So I have to be patient _____ him[ ]

My cousin used to ________ online too late, but now she is used to ________ to bed early.

How could she be so calm in front of so many people It is really _______me.