第5题: [单项选择]A) The man should phone the hotel for directions. B) The man can ask the department store for help. C) She doesn’t have the hotel’s phone number. D) The hotel is just around the corner. 参考答案:A 答案解析:[听力原文] M: Excuse me, but could you tell me how to get to the Friendship Hotel I thought it was o
第6题: [单项选择]MR成像过程中,金属产生伪影是因为() A. 干扰主磁场的均匀性 B. 部分体积效应 C. 产生热量 D. 电阻大 E. 密度大 参考答案:A 答案解析:金属异物可局部形成强磁场从而干扰主磁场的均匀性,局部强磁场可使周围旋进的质子很快丧失相位,而在金属物体表面出现一圈低信号"盲区"或图像出现空间错位而变形失真。