Keep your child off drugs,  ________ it will ________ many serious health and behavior problems.

Help others whenever you can      you’ll make the world a nicer place to live.  

_____Peter____ Bill is good at sports. They both play basketball really well.

Hold on to your dreams, _____ they will come true some day.

—You look tired. What’s wrong with you, Wang Ming?
—Last night I watched TV      12 o’clock.

—Did you give Tom a call?
—I didn’t need to , ________ I’ll see him soon.

She didn’t know__________she could express her ideas clearly when she was invited to speak at the meeting.

Jim was watching a late night film______ the television went blank.

Everyone tells me I'm a good speaker, ______ I really don't like speaking in public.

— Could we practice playing the guitar in the hall, Sir ?                  
—No , ___________ you have the principal’s (校长) note.