A:desig
B:are designed
C:are designing
D:are being designed
① ____ A. summer B. winter C. season
② ____ A. which B. there C. why
③ ____ A. because B. pretty C. beautiful
一辆汽车从上午9时到下午2时,一共行驶了325千米,这辆汽车平均
每小时行驶多少千米?
小华用如图所示的电路测小灯泡功率.电路中电源电压恒为4.5V,电压表的量程为O~3V,电流表的量程为0~0.6A,滑动变阻器的规格为“20Ω lA”,灯泡标有“2.5V 1.25W”字样。若闭合开关,两电表的示数均不超过所选量程,灯泡两端电压不允许超过额定值,不考虑灯丝电阻的变化,则下列说法正确的是