[单项选择]How did the science of preparing metals for use happen A. By any planned purpose. B. By chance. C. With fire. D. On the part of those who were concerned about it.
参考答案:B 答案解析:[精解] 文章细节题。浏览全文,就可以找到"…it(the science of preparing metal for use)happened more by chance than by any
第5题: [单项选择]______ in his position, I'd have left there immediately. A. was I B. I was C. Were I D. I were 参考答案:C 答案解析:[解析] if引导的条件句的虚拟语气中,有三种从句部分倒装的情况:(1)与现在事实相反的从句中有were, (2)与过去事实相反的从句中有had done,(3)与将来事实相反的从句中有should
第6题: [单项选择]你认为,从现实走到理想,这之间是() A. 一条弯弯的小河 B. 一座高高的雪山 C. 一片毒蛇猛兽出没的密林 D. 一片没有绿洲的荒漠 参考答案:C