Try to buy one before all the tickets ________.
| A．will be sold | B．will be sold out | C．are sold | D．are sold out |
—_______have you visited Nanjing? —Three times.
| A．How often | B．How many times | C．How long | D．How soon |
He ________be at home because the light in his room is on.
| A．must | B．can’t | C．can | D．mustn’t |
We ________ our hands while they were singing on the stage.
| A．clap | B．have clapped | C．were clapping | D．are clapping |
—Have you ever ________ to the Great Wall? —Yes, I _______ there last autumn.
| A．gone; went | B．gone; have been |
| C．been; went | D．been; have been |