如图是新型节能应急台灯电路示意图，台灯充好电后，使用时可通过调节滑动变阻器接入电路的阻值R改变灯泡的亮度，假定电源电压、灯泡电阻不变，则灯泡两端电压U随R变化的图象是：

A.

B.

C.

D.

短文改错。

     This morning I got up early and went to school as usually, only to find there were nobody in the

classroom because it is Sunday. "How a bad memory I have!" I couldn't help laughing. Stand in

front of the school gate, I began to wonder what to do next. Suddenly a good idea occurs to me.

"Why not get together with some good friends for a picnic in such a fine weather?" I immediately

telephoned some of my best friends, but they all agreed to join me. About two hours late, we finally

arrived a pleasant park with trees and flowers here and there. We really enjoyed us greatly.