1. Study harder, or you won't catch up with others.
    ______ ______ ______ study harder, you ______ fall behind others.
2. My brother didn't go to work. He stayed at home, instead.
    My brother ______ at home ______ ______ ______ to work.
3. How do you like his idea?
    ______ do you ______ his idea?
4. She has a headache.
    She has ______ ______ ______ in her head. Her head hurts.
5. My mother bought me a bike as a birthday present.
    A bike ______ ______ ______ ______ by my mother as a birthday present.

1. Don't r         it as a failure. You have tried your best after all.
2. His idea often i           her decisions.
3. You won't catch up with your classmates u       you do it day and night.
4. Did you form any close f          when you were in China?    
5. The weeks w           slowly by and the little girl forgot the unhappy thing at last.

A. but
B. so
C. or
D. and