问题
选择题
The new secretary is supposed to report to the manager as soon as she _______. [ ]
A. will arrive
B. arrives
C. is going to arrive
D. is arriving
答案
答案:B
The new secretary is supposed to report to the manager as soon as she _______. [ ]
A. will arrive
B. arrives
C. is going to arrive
D. is arriving
答案:B
LED(发光二极管)日光灯是未来家庭照明的首选,前景广阔。下表是LED日光灯与普通日光灯的技术参数对比的数据。若使下表中的LED灯正常工作,应该选用 只 联在家庭电路中工作,并且它们的发光效果与对照的普通日光灯高出 ____%,若每天照明3个小时,一个月(30天)共节电 kwh。
名称 | 发光二极管(LED) | 普通荧光日光灯(CFL) |
额定电压/V | 22 | 220 |
额定功率 | 1.6W | 灯管功率32W 附加电路功率4W |
亮度/ lm | 550 | 440 |
寿命/h | 30000 | 3000 |
价格/元 | 20 | 25 |