Much ______ to be done.
He was so deep in thought,thinking of the problem ________ he knocked into the tree without noticing it.
________ all of them are strong candidates,only one will be chosen for the post.(2011·陕西,19)
Please call my secretary to arrange a meeting this afternoon,or________it is convenient to you. (2011·江西,29)
Jack wasn’t saying anything,but the teacher smiled at him________he had done something very clever. (2011·湖南,33)
At school,some students are active ________ some are shy,yet they can be good friends with one another. (2012·四川,4)