节日中有一串小彩灯闪烁发光，若通过第20只小彩灯的电流为20 mA，则通过第5只小彩灯的电流为_____μA．
2×104
E-mail, as well as telephones, ______ an important part in our daily life. [ ]
A. is playing
B. play
C. are playing
D. have played
长期（）聚积的不满，会爆发在平时的生活中。
