—How come everything tastes bitter?—Well, things ________ taste different to you when you are suffering a cold.

—Do you think the phone is genuine(真品)? —I don’t think it ______ be a fake, as this shop has a very good reputation. 

Without gravity, we _____ walk on the ground as freely as we do now. 

I talked for a long time, and in the end I_____ make her believe me. 

— I phoned you yesterday morning. A girl answered, but I didn’t recognize the voice.— Oh, it __________ my younger sister. She was in my room at that moment.