When he ________ with his sister, he suddenly ________ into tears.

[　　]

Knowing ________, as a matter of fact, one shouldn't know is a terrible thing.

[　　]

In some countries, ________ are called “Public School” are not owned by the state.

[　　]

The first text books ________ for teaching English as a foreign language came out in the 16th century.

[　　]

—I must apologize for________ ahead of time.

—That's all right .

[　　]

—I usually go there by plane?

—Why not ________ by train for a change?

[　　]

Do you know the boy ________ under the big tree?

[　　]

I often have my clothes ________ and he often has his mother ________.

[　　]

A．to be washed; to wash his

B．washed; to wash his

C．to wash; wash his

D．washed; wash his

In some pats of London, missing a bus means ________ for another hour.

[　　]

A．waiting

B．to wait

C．wait

D．to be waiting

Prices of daily goods ________ through a computer can be lower than store prices .

[　　]

A．are bought

B．bought

C．been bought

D．buying