How long are you staying here?—That __________ the weather.

Look, your sister is playing the piano over there.－She ______ be my sister. She has gone to America.

She didn’t allow the accident to discourage her. On the contrary, she began to work.

The movie is so__________, and many of us are ____________ in it.

Whose book is this? —It ______ be Linda’s. It has her name on it.