I work harder at my lessons this year _____ I have made good progress.

—When did your daughter go to sleep last night?
—She didn’t go to bed ______ she finished her homework.

________ I got on the bus, he got off.

Frank often wears a mask ________he can keep fit in the foggy and hazy (霾) weather.

- How do you like the concert given by F.L.R.?
- Exciting, _______ one piece of the music wasn't played quite well.

Susan was reading a newspaper on the train_________ a strange old man come over.

—How are you going to spend this weekend? 
—_________ the weather is fine, we’ll climb Mount Tai.

—I  have  no  idea ____________   tell her  the  bad  news. 
—I think tomorrow is the best time.

Our team tried our best, ________ we failed the match at last.

The earth will become worse and worse ________ we do something to stop her from being polluted.