— ______ are you going to Guangzhou?— I’m taking the plane. 

----Would you like to lend me some money?----I’d love to, _______ I left my purse at home.

—— Hurry up. The bus is coming! —— Oh, no, we mustn’t cross the street ______ the traffic lights are green.

Sometimes I feel bored and don’t  know ______ to do.                          

Check again,           you’ll make fewer mistakes.