To keep safe _______ an earthquake, you should remain at a spot in your room where nothing may fall on you.
(2013·北京卷) I have an appointment Dr. Smith, but I need to change it.
(2013·大纲卷)A serious study of physics is impossible some knowledge of mathematics.
It will be a big help if you go to the store and get what we need for dinner._____, I’ll set the table.
(2013·新课标Ⅱ卷) A serious study of physics is impossible some knowledge of mathematics. against B. before C. beyond D. without
It was a real race _______ time to get the project done. Luckily, we made it.