Lucy is a naughty ________ nice girl. (   )

A．and

B．but

C．then

This knife is old ______ sharp. (    )

A．and

B．or

C．but

They like skirts, ________ we like dresses. (　　)

A．but

B．or

C．too

用所给词的适当形式填空。
ring    cry    but   come   watch
1. My father is working on the computer, but my brother starts to ________.
2. My mother is cooking dinner, but the bell ________.
3. “Come in，please!” I say. My friend Lucy ________ in.
4. Mr Smart is reading a book and Mrs Smart ________ TV.
5. Lin Tao is doing his homework, ________ the phone rings.

I like cake, ________ I don’t like ice cream. (   )

A．and

B．but

C．no