22.I’m terribly sorry to turn you down this time, but I promise I will ________ to you next time.
Someone called me up in the middle of the night, but they hung up _____ I could answer the phone.
Peter’s mother kept telling him that he should give up smoking, but _____ didn’t help.
It’s quite different from _____ I read last month.
Three-fourths of the homework _____ today.
When you want to write a person’s biography(传记),you must find out _____ about his or her life.