民间常用“拔火罐”来治疗某些疾病，方法是将点燃的纸片放入一个小罐内，当纸片燃烧完时，迅速将火罐开口端紧压在皮肤上，火罐就会紧紧地被“吸”在皮肤上。其原因是，当火罐内的气体
A．温度不变时，体积减小，压强增大
B．体积不变时，温度降低，压强减小
C．压强不变时，温度降低，体积减小
D．质量不变时，压强增大，体积减小

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阅读下列短文，从每题所给的A、B、C和D项中，选出最佳选项，

Lisa was running late. Lisa，25，had a lot to do at work，plus visitors on the way: her parents were coming in for Thanksgiving from her hometown. But as she hurried down the subway stairs， she started to feel uncomfortably warn. By the time she got to the platform，Lisa felt weak and tired--maybe it hadn’t been a good idea to give blood the night before，she thought. She rested herself against a post close to the tracks.

Several yards away，Frank，43，and his girlfriend，Jennifer，found a spot close to where the front of the train would stop. They were deep in discussion about a house they were thinking of buying.

But when he heard the scream，followed by someone yelling，“Oh，my God，she fell in!” Frank didn’t hesitate. He jumped down to the tracks and ran some 40 feet toward the body lying on the rails. “No! Not you! ”his girlfriend screamed after him.

She was right to be alarmed. By the time Frank reached Lisa，he could feel the tracks shaking and see the light coming. The train was about 20 seconds from the station.

It was hard to lift her. She was just out. But he managed to raise her the four feet to the platform. so that bystanders could hold her by the grins and drag her away from the edge. That was where Lisa briefly regained consciousness，felt herself being pulled along the ground，and saw someone else holding her purse.

Lisa thought she’d been robbed. A woman held her hand and a man gave his shirt to help stop the blood pouring from her head. And she tried to talk but she couldn’t，and that was when she realized how much pain she was in.

Police and fire officials soon arrived，and Frank told the story to an officer. Jennifer said her boyfriend was calm on their 40-minute train ride downtown—just as he had been seconds after the rescue，which made her think about her reaction at the time. “I saw the train coming and 1 was thinking he was going to die，”she explained.

41. What was the most probable cause for Lisa’s weakness?

A. She had run a long way.

B. She felt hot in the subway.

C. She had done a 1ot of work.

D. She had donated blood the night before.

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用现代汉语解释下列句子。(5分)

(1)尧咨讽转运使出公，不使居府中。

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The passage is probably followed by a concluding paragraph about .