–Do we have to talk with Jack about that matter?–Yes, I think we __________.

No matter how healthy you _____be，you need to consult a doctor from time to time.

—Listen! Is that Millie singing?—No. It _____ be Millie. She has gone to Beijing.

Johnny, you      play with the knife; you     hurt yourself.

I want        a book for my granddaughter Linda who is 2 years old.