___ China’s reform（改革）and opening up in fate 1978, its quick development has aroused worldwide attention

A serious study of physics is impossible ________ some knowledge of mathematics.

Were you at home at 9:00 pm yesterday— Yes, I for a call from Paris at that time.

Does Daniel ________ after school—No, he doesn’t.

Mr. President, do you plan toeducate your two daughters to be officials—To tell you the truth, I hope they can dowhatevertheir interests.