_____ he graduated from college, he became a success in business. 

(2009年合肥市高三第一次教学质量检测)The police tried to get some clues from the suspect，but he remained     ．

She seems_     happy in her new job since there is nothing troublesome to bother her. 

The charity sale our school organizes every year has taught us much that we would never have _____ learned in class.

（2014年安徽省合肥市高三第三次教学质量检测）23. -- Don't you think Carl was brave to go wingsuit flying?-- Personally, I think he was ______. He shouldn’t have risked his life to do so.