在换热器中，套管式换热器的特点为( )。
A．换热系数大
B．不易发生泄漏
C．耐压较低
D．能耐较高压力
参考答案：D
The College Entrance Examination is around the corner, but we should strike a
between study and relaxation.
A．association
B．balance
C．compromise
D．obstacle
数字化彩超的关键技术是
A．宽频探头B．二次谐波成像C．数字或波束形成仪D．多道电子开关选择发射及接收的振子E．预置多种优化检查条件
