单选题
The American expression" burning your bridges' means acting in such a way which you de stroy any chance of turning back or changing your actions. It gets its name from war. An army that is forced back across a river may decide to burn the bridge 41 crossing it. In this way, the army 42 its enemy from using the bridge. 43 , the army also destroys its own chance to 44 back across the river. Most people who" burn their bridges today don't 45 the army. But 46 those armies, they move in a different direction with 47 chance of turning back. There is one other 48 that all bridge burners should not forget. It is a warning. "Don't cross your bridges 49 you come to them. "The meaning is clear: wait until the right time before you 50 .
【正确答案】
B
【答案解析】[解析] 本文是讲burning your bridges这个词语的故事。它来源于战争，一个军队过完一座桥后，烧掉了这座桥，这样可以阻止敌人用这座桥，挡住他们的来路，同时也毁掉了自己回去的路。用中国的话来说，即“置死地而后生”。
【正确答案】
A
【答案解析】[解析] prevent sb. from doing sth. 是固定词组，意思是“阻止某人做某事”。