The policeman told us __________ the street when the traffic light was red. 

—Why did you buy so many flowers? --Because today is a special day.  My parents ________ for twenty years .

To live a green life, we try_________ more energy and produce less pollution.

---How about the trip to Shanghai, Kitty?---Everything was fantastic if our car did not _______ for some times on the way.

I feel it hard to keep up with my classmates in study and sometimes I lose heart. But whenever I want to ________ , my teacher always encourages me to work harder.