I have nothing to do but ________ my daughter in the evening.

The environment is becoming worse and worse. I think we should do something to ____ people ____ cutting the trees in order to protect the earth.

---How long did it _____ you to work out the difficult maths problems?---I ______ about half an hour on it .

-- Don’t ________. Keep working hard and you will win the match. -- Thank you, Mr. Zhang. We’ll try our best.

 Every year, we ______ a school trip to Zhou Enlai Memorial Hall.