________ with the size of the whole earth, the highest mountain does not seem high at all.

[　　]

A. When compared

B. While comparing

C. Compare

D. Comparing

Would you read my letter and correct the mistakes, if ________ ?

[　　]

I won't go to his birthday party unless ________.

[　　]

________, we'll build another railroad in this area.

[　　]

A. If possible

B. If not

C. If it will be possible

D. If we are possible

________, he was thrown away into the river.

[　　]

A. After killed

B. After being killed

C. After killing

D. After to be killed

________, the bird can live as long as five years.

[　　]

A. If taking care of

B. If taken care of

C. If take care of

D. If to take care of

________, he didn't attend the meeting.

[　　]

A. Because ill

B. Because of being ill

C. Because being ill

D. Because of ill

Although ________, he managed to run away.

[　　]

A. he was frightening

B. he is frightened

C. frightening

D. frightened

He came across the picture while ________ to New York.

[　　]

________ happens, I'll stand on your side.

[　　]