振荡波
参考答案:
波动中水质点围绕其静止位置沿着某种固有轨迹作周期性的来会往复运动,质点经过一个周期后没有明显的向前推移的波浪。
下列情况中,适合进行单纯未闭动脉导管结扎术的是().
A.合并Eisenmenger综合征
B.合并主动脉狭窄
C.合并细菌性心内膜炎
D.合并室间隔缺损
E.以上都不是
He insisted that he _____ the best, so he insisted that he _____ the work all by himself.
A.was; do
B.be; do
C.be; did
D.had been; had done