装拆接地线应使用()。挂接地线时应先接接地端,再接设备端,拆接地线时顺序相反。
A.绝缘胶布
B.静电感应防护服
C.绝缘棒
D.戴绝缘手套
E.绝缘接地线
参考答案:C, D
如图所示的光学现象中,下列描述或解释不正确的是
A.图(a)中,小孔成的是倒立的虚像
B.图(b)中,人配戴的凹透镜可以矫正近视眼
C.图(c)中,白光通过三棱镜可以分解成红、橙、黄、绿、蓝、靛、紫七色光
D.图(d)中,漫反射的光线尽管杂乱无章,但每条光线仍然遵循光的反射定律
when the dispute over duty payment arises between the duty payer and the Customs, the duty payer should first pay the duty and then, within ______ days of the issuance of the duty memo, apply to the Customs in writing for a reconsidertation of the case.
A.10 days
B.20 days
C.30 days
D.50 days