Now that their parents are dead, the poor boy doesn’t know ________ the money they left.

What can I do for you, sir? ——I want ____.

______ do you write to your parents? 　　 — Once a month. [ ]

I find _______ necessary to take some warm and dry clothes with us during the walk.

Lisa, are you going to play ______ violin after school this afternoon? —No, and I’m going to play ______ chess with Tina.