—Can I tell Peter about the news?—No, I don’t want anyone else to know it. You _______keep it to yourself.

Those who failed to get into the art exhibition ________ disappointed as many of the artists who should have appeared did not come. 

If you ______ smoke, please go outside.

It    be difficult to get a train ticket during traditional Chinese Spring Festival this year because there are many ticket windows.

I __________use a clock to wake me up because at six o'clock each morning the train comes by my house.