Bicycling is a good exercise;________ it does not pollute the air.

It was very cold outside and we had       to go, so we had to stay at home .

Daming didn’t take a photo in the museum. I didn’t,  _______

—_______is your husband?— A cook. He works in a restaurant near our home.

Li Xing’s illness(病) is very_____. You must take his illness ______.