He is one of the students who, I am sure, always do ____ best.

You ought to have given them some advice.— , but who cared what I asked?

I want to buy a nice present _____ my mother and I must give it _____ her myself.[ ]

What’s your sister doing? — She is singing a song _______ my mother. [ ]

It was on June 10,2013＿＿＿Shenzhou-10 spacecraft was sent up into space.