装卸气瓶时,在同一车箱内不准有____人以上同时往车上装瓶。
A.2
B.4
C.3
参考答案:A
— We must start out early, _____ possible traffic delay.
— Yes, we can easily _____ in it.
[ ]
A. allow for; get struck
B. allowing for; get struck
C. allow for; get stuck
D. allowing for; get stuck
小刚家新买了一个电炉,它的额定电压是220V,额定功率是880W,让电炉在额定电压下工作,把5kg的水从12℃加热到100℃.[不计热损失,C水=4.2×103J/(kg•℃)]
(1)该用电器正常工作时的电流多大?电阻多大?
(2)水需要吸收多少热量?
(3)加热的时间是多少?