从主动脉瓣关闭到二尖瓣开放这一时期称为（）.
A.等容舒张期
B.等容收缩期
C.心房收缩期
D.快速射血期
E.快速舒张期
参考答案：A
The result was not as good as expected but the ________ on his face told us that he was still very happy.
A．expression
B．impression
C．celebration
D．appearance
以下不属于强制检定计量器具的是：（）。
A.接地电阻仪
B.计费用互感器
C.线损考核用电能表
D.单位最高计量标准表
