1 . You’ll never speak English well________you often practice it.

A．unless

B．if

C．or

D．otherwise

2 . He has read a lot of books on arts        he wants to be an artist in the future.

A．because

B．though

C．once

D．unless

3 . The little girl was________excited________she couldn’t say a word.

A．so; that

B．too; to

C．very; to

D．so; to

4 . Batteries are not allowed by airlines in checked luggage, as they might explode due to overheating. (英译汉)