—What would you do if you had your fingers ______?  —If I _______ you. I should ask the first-aid. 

Why _______ him some advice on how to do it?

They      _ the train until it disappeared in the distance.

---Excuse me , Sir . But smoking is not allowed here. ---Sorry, I didn’t see the sign. I’ll ___________________ my cigarette at once.

A low-carbon(低碳) lifestyle has an effect        our daily life. People are paying more and more attention to         energies these days.