As we all know, it is usually cold in this place in January, but it _____ be warm sometimes.

The post office is about 1 kilometer __________.

---Listen! Is Kitty in the next room?  ---No, it ______ be Kitty. She has gone to Beijing.

The police still haven’t found her, but they’re doing all they      .

I always go to sleep ___________ the light on.