---______ does she dance every day?
---For two hours.
| A．How many | B．How long | C．How soon | D．How often |
— What’s your plan for this weekend?
— We will go for a picnic by the river _______ it rains.
| A．unless | B．if | C．but | D．because |
—Why was he late for school yesterday?
— He overslept. By the time he got to the bus stop, the bus ________ already ______.
| A．has; left | B．had; left | C．was; leaving | D．have; left |
—Heavy smog (雾霾 )in eastern and central China seems to get more and more serious.
—I agree. Something to deal with it.
| A．has done | B．is doing | C．must be done | D．must do |
— Who is your favorite writer?
— Mo Yan. I like writers _________ tell stories well.
| A．where | B．when | C．which | D．who |
Tom finds _________ difficult to learn Chinese well.
| A．it | B．that | C．this | D．him |