I ________the dog ________a walk every day.

Hey, Molly, You______ on the phone just now. But you weren’t here and the man left a phone number.-Oh? I was in the library.

We are sure one day the air in Beijing will be much ______ than today.

We should consider the students’ request ______ the school library provide more books on popular science.

Although punctual himself, the professor was quite used ________ late for his lecture.