I ________ use a clock to wake me up because at six o’clock each morning the train comes by my house.

David, get up early, ________then you’ll catch the early bus. 

一What are you going to do this weekend?一Well，we’ll clean up the city parks _______ it rains .

—______ is your best friend?— Linda, I guess.

You have ______ money than me, but you have ______ friends than me.