The temperature can drop ________zero when winter comes.
— Does the tiger come from Europe?— No, it doesn’t. It comes from ________.
I like Britney Spears. She’s ________ favorite singer.
--- Have you got some water to drink?--- Here you are. There _______ still some in the bottle.
---Mum, can I go to the zoo with Linda? ---When your homework _______, you can.
I can’t forget the time _______ the earthquake happened in Yushu.