闪烁
参考答案:
眼睛会感觉光的周期性时间变动的现象,称为闪烁
---Do you think Peter is free today?
---I don’t think so. Recently he has been ______ the most of his time to prepare for the final examinations.
A.making
B.planning
C.using
D.getting
在距离接触网带电部分()的导线、支柱、房顶及其它设施上施工时,接触网可不停电,但须有接触网工或经专门训练的人员在场监护。
A、1~3米
B、2~4米
C、3~5米
D、4~6米