利用DME进行定位，要求至少同时接收到（）DME信标的信号。
A.1个
B.2个
C.3个
D.4个
参考答案：B
Frank , with his two sisters , _____ London by train which _______ at 8:30 next morning .
A．is leaving for ; will leave
B．are leaving for ; leaves
C．is leaving for ; leaves
D．will leave for ; will leave
教学过程是指教师把（）等内容以有效的方式传授给学生并引导学生主动建构自己知识的过程。
A.知识技能
B.学习过程
C.学习方法
D.应考策略
