【简答题】如下图所示电路,用叠加定理,当2V电压源单独作用时,U’=V;1A电流源单独作用时,U”=V。(注意:答案不写单位,就写两个数字,中间空一格)【图片】
【简答题】如下图所示电路,其中 R 1 =1 Ω, R 2 =2 Ω, R 3 =3 Ω, R 4 =4 Ω, i s =1 A, u s =1 V,利用叠加定理,可求得电压u= ( )V 。
【单选题】如图所示的是甲,乙两种固体物质的溶解度曲线,根据图中的相关信息判断下列说法正确的是( )
A.
在t 1 ℃时,甲、乙两种饱和溶液溶质质量分数一定相等
B.
温度由t 2 ℃降到t 1 ℃时,物质甲的饱和溶液的溶质质量分数不变
C.
t 2 ℃时,物质甲的溶解度大于物质乙的溶解度
D.
通过降低温度的方法,均可以使甲乙两种溶液中析出晶体
【单选题】听力原文:W: Bob, what happened? You look a mess! M: I feel even worse than I look. I was tiding along the road when a dog began barking at me. I turned to have a look, and I bumped into another bike. I wa...
A.
He was bitten by the dog.
C.
He was hurt by another bike.
D.
He had a bad fall off his bike.
【单选题】According to Text A of Unit 1, young people of generation Z may opt for headphones at work, collaborating and socializing in chat rooms.
【单选题】The car bumped (颠簸) along the _____ road.
【单选题】楼板、屋面板、楼梯段和楼梯平台等轮廓线采用
【多选题】关于直方图的用途下列说法不正确的是( )。