It is unfair, ________?

[　　]

－Listen, someone is knocking at the door?

－Who can ________ be?

[　　]

Mary is respected ________ a good maths teacher.

[　　]

Whenever he makes a promise, he will ________ it.

[　　]

We ________ in the snow.

[　　]

I first met Lisa three years ago. She ________ at a radio factory at the time.

[　　]

When the bird got well, we will ________.

[　　]

－Do you have anything more ________, sir?

－No. You can have a rest or do something else.

[　　]

American eat ________ vegetables per person today as they did in 1910.

[　　]

A．more than twice as many

B．more than twice

C．as twice a many as

D．twice as many as

I simply couldn't understand how it ________ that you did so much work within such a short time.

[　　]