多普勒超声心动图可分为频谱多普勒和彩色多普勒血流成像两种。前者又分为脉冲多普勒和连续多普勒。
参考答案：对
-------Take a break, Amy. You ________ on the piano all morning.
-------I’d like to, but this time next week I _______a concert at Music Hall.
A．have practiced, will give
B．are practicing, am giving
C．have been practicing ,will be giving
D．will have practiced, have been giving
牙体缺损修复时，修复体与牙龈组织的健康有关的是（）
A.修复体龈边缘的位置
B.修复体龈边缘的外形
C.修复体龈边缘的密合性
D.修复体龈边缘处的牙体预备形式
E.以上都有
