—Do you think our teacher is　　　　？—Yes， he always corrects our homework and prepares his lessons　　　　. 

---Students should devote most of their time to studying rather than playing computer games.                                                       ---________.No pains, no gains.

Tell your brother to come _____, because it's going to rain in a minute or two.

—Where are the visitors from?—_______from South Africa.

-----Our women athletes achieved great success in the Vancouver Winter Olympic Games.----- Yes. No one could perform _____, I think.