—The plane is due to take off at 7:50 from the airport. ______ we fail to arrive there in time?—Try to take another flight then.
19. I don’t know why he blamed the accident _____ me.
18. The dying man is _____ the help of the doctor.
17. Hunan lies _____ such provinces as Hubei, Jiangxi, Guangdong, Guizhou and Chongqin.
16. Mary answered all the questions _____ the last one, which she had never heard of before.
15. The doctor bent _____ the boy and checked his wound.