—When were you born? —I was born ________ the morning of February 25th,1997.
________ my surprise, the twins have nothing _______ common.
---Do you know sound travels very fast? ----Yes. But light travels _______ sound.
Paper-making is one of _______ of ancient China.
Could you please give some _______ to the _______ teachers?
Please wait here. I’ll be back in _______ hours.