27. Finish your homework or you can't go out with your friend.

A. Unless you finish your homework, you can go out with your friend.

B. If you don't finish your homework, you can go out with your friend.

C. If you don't finish your homework, you can't go out with your friend.

D. If you finish your homework, you can't go out with your friend.

28. It took me 4 hours to read the first chapter of the book.

A. I spent 4 hours reading the first chapter of the book.

B. I spent 4 hours to read the first chapter of the book.

C. I spent 4 hours to reading the first chapter of the book. D. I spent 4 hours read the first chapter of the book.

29. Snowboarding is more dangerous than tennis.

A. Tennis is as dangerous as snowboarding.

B. Tennis is not as dangerous as snowboarding.

C. Tennis is as dangerously as snowboarding.

D. Tennis is not as dangerously as snowboarding.

30. Nobody saw her book at the party last night.

A. Her book was seen at the party last night.

B. Her book was not seen at the party last night.

C. Her book were seen at the party last night.

D. Her book were not seen at the party last night.