题目

In fact he knows this place very well, for he ________ there three times. A. has been         B. has been to          C. has gone         D. has gone to 答案：A 【解析】 试题分析：句意：实际上，他非常了解这个地方，因为他已经去过那里三次。there是副词，前面不应有介词。have been(to)已经去过，现在已回来；have gone(to)已经去了，现在还没回来。因此，选A。2、已知|x2-5|=10，则x2=（15）．