What color is our national（国家的）flag(旗帜)? It’s ________.

May I speak to Miss Wang?—Sorry. She isn’t in. She __________ to Hong Kong.

There are so many kinds of computers in the shop. I really don’t know ______ to choose.

Why not the music club?—Sorry, I can’t sing or dance. [ ]

We’ve been _____ for her for 5 hours.