—I don’t know ____ .—Because he has to look after his mother.
—Terra, you shouldn’t be so ______. You always leave your things everywhere.—Sorry, mom. I’ll put them away soon.
By the time I got home, Gina and her sister ______ their project already.
—I think you can ______ money by yourself to buy a present for your mother.—OK. I’ll try. I’ll not let a penny waste.
—I think the man over there must be Bob.—It ______ be him. He has gone to Paris.
Everyone knows that Diaoyu Island belongs ______ China.