甲骨文不是一种象形文字。

下列各方组成药物中不含生姜的是( )

A．吴茱萸汤

B．真武汤

C．小青龙汤

D．炙甘草汤

E．温经汤

如图甲所示为一种研究高能粒子相互作用的部分简化装置，粒子先由k个加速电场从静止开始加速后，被导入装置送入位于水平面内的圆环型真空管道。每个加速电场电压均为U，在管道内有n个控制粒子转弯的圆形磁场，连续均匀分布在整个圆周上，每个圆形磁场的磁感应强度大小均为B。粒子在环形管道中沿管道中心线做半径为R的匀速圆周运动，经过每个圆形磁场时，入射点和出射点都在同一条直径的两端（如图乙所示）。粒子重力不计，且不考虑粒子的相对论效应，（k、U、R、B、n为已知量）求：  

（1）粒子进入圆环型真空管道时的速度大小v；

（2）粒子经过每个圆形磁场区域的时间t；

（3）环形管道的内环半径a．

Many years ago, when I was fresh out of school and working in Denver, I was driving to my parents’ home in Missouri for Christmas. I stopped at a gas station(加油站) about 50 miles from Oklahoma City, where I was planning to stop and visit a friend. While I was standing inline at the cash register, I said hello to an older couple who were also paying for gas.

I took off, but had gone only a few miles when black smoke poured from the back of my car. I stopped and wondered what I should do. A car pulled up behind me. It was the couple I had spoken to at the gas station. They said they would take me to my friend’s home. We chatted on the way into the city, and when I got out of the car, the husband gave me his business card.

I wrote him and his wife a thank-you note for helping me. Soon afterward, I received a Christmas present from them. Their note that came with it said that helping me had made their holidays meaningful.

Years later, I drove to a meeting in a nearby town in the morning. In late afternoon I returned to my car and found that I’d left the lights on all day, and the battery was dead. Then I noticed that the Friendly Ford dealership—a shop selling cars was right next door. I walked over and found two salesmen in the showroom.

"Just how friendly is Friendly Ford" I asked and explained my trouble. They quickly drove a pickup truck to my car and started it. They would accept no payment, so when I got home, I wrote them a note to say thanks. I received a letter back from one of the salesmen. No one had ever taken the time to write him and say thank you, and it meant a lot, he said.

"Thank you" are two powerful words. They’re easy to say and mean so much.

The author planned to stop () at Oklahoma City.

A．to visit a friend

B．to see his parents

C．to pay at the cash register

D．to have more gas for his car

什么叫电弧？断路器为什么要有灭弧装置？

化学学稳定性