下列选项中,属于动植物共有的糖类是
A:葡萄糖 核糖 脱氧核糖
B:葡萄糖 淀粉 果糖
C:淀粉 脱氧核糖 乳糖
D:麦芽糖 果糖 乳糖
下列各句中,没有语病的一句是( )
I'm Yangyang. I like table tennis. I don't like skipping. I have a bike, and I like riding my bike. My father likes swimming. He likes tea and coffee. My mother likes skipping. And she likes her brown cat .
一个电源的路端电压U随外电路电阻R的变化规律如图(甲)所示,图中U=12V的直线为图线的渐近线.现将该电源和一个变阻器R0接成如图(乙)所示电路,已知电源允许通过的最大电流为2A,变阻器的最大阻值为R0=22Ω.求: