The air in Taizhou is getting ________ cleaner now than a few years ago.
I enjoy fresh air so I always let the window open ________ it is really cold.
We will have no water to drink ________ we don't protect the earth.
—You bought the car about ten years ago? —Yes.________ it's old,it still runs well.
Mark isn't coming to the concert ________________ he has got too much work to do.
-When will you go back to your hometown? - _______.