题目

During the examinations we are supposed to remain in our seats, fix our eyes on the papers, ______anyone. A．instead of speaking to                            B．and not to speak C．rather than speak                           D．but shouldn’t speak 答案：B在北方的冬季，常见的几种物态变化现象中，属于凝华的是（　　）A．室外冻冰的衣服变干B．房间窗户玻璃的内表面出现冰花C．湖面结了厚厚的一层冰D．正在跑步的人，口中呼出“白气”