广播谈话是一种谈话体评论，它区别于其他广播评论形式的基本特点是（）
A.面对面交谈
B.类交流
C.直接对话
D.热线沟通
参考答案：B
At the beginning of class, the raise of desks could be heard outside the classroom. [ ]
A. opened and closed
B. to be opened and closed
C. being opened and closed
D. to open and close
诊断冠心病最有价值的辅助检查是
A．超声心动图
B．常规心电图
C．心音图
D．心电图运动负荷试验
E．动态心电图
