The problem he referred to _____ difficult, but is isn’t at all.
You may use the room as you like ___ you clean it up afterwards.
John plays basketball well, ___his favorite sport is badminton.
Mr.Smith was_________ to be a doctor but he became a teacher when he grew up.
I’m sorry I can’t go to the film with you because I have a lot of things to _________.
Children’s brains can’t develop properly_______ they lack protein(蛋白质).