Beijing, the capital of China, is one of __________ cities in the world.

Be careful . You _______ cross the road when the traffic light is red . The traffic is heavy at this time of day .

Mary doesn’t like blue, so her mother ____ buys blue clothes for her.

I feel tired and sleepy.— Why not consider_________?

the red switch on the left and the flying machine will swiftly go up into the air and its journey.