内部接线
参考答案：
通常指灯具内部且附带在灯具的接线。它构成外部接线或电源电缆的接线端子与灯座、开关和类似部件的接线端子之间的连接
Safety in school has been of great concern because of frequent reports about accidents _______ students got injured or killed while in school .
A．that
B．when
C．in which
D．for which
“二元经济”是指( )。
A．发达国家与发展中国家经济的不一致B．在欠发达国家中，男人和女人收入之间的不一致C．在欠发达国家中，较高收人与较低收入的不一致D．在欠发达国家中，农村与城市生活之间的不一致
