第9题: [单项选择]从使用角度评价彩色多普勒血流显像仪,哪项是质量差的标志() A. 空间分辨率、速度分辨率、动态分辨率均高 B. 检出血流敏感度高 C. 显示图像均匀性好 D. 彩色血流效果好 E. 提高灰阶图像增益时,彩色图像质量下降 参考答案:E 答案解析:提高灰阶图像增益时,彩色图像质量下降,不能清楚辨识血管结构,成像质量差。
第35题: [单项选择]Not until Kentucky's Mammoth Cave had been completely explored in 1972______. A. when was its full extent realized B. that its full extent realized C. was its full extent realized D. the realimtion of its full extent 参考答案:C 答案解析:not until结构位于句首时,主句部分需要倒装,选项C正确。