阅读理解.
For an American, or a foreigner here, any chance to have a social life is welcome. But
what happened last night made me think I may be better off having no life while I'm in
Baghdad.
Friday evening,l was on my way with an American journalist friend to his welcome party.
When we got to a checkpoint,we were told to get out of the car to be searched,which is
normal procedure. We waited under a tent,as our car was examined on the other side
of a wall. We couldn't see what was happening but we figured we would hit the road soon.
But the search was taking longer than expected, probably because of a car bomb
threat that had been reported earlier. Then we noticed the officers put their helmets(头盔)
on. Never a good sign.
Our Iraqi driver then noticed that our other Iraqi driver and guards who were in a
second car were standing facing a wall. We had gotten separated from them at the
checkpoint. We told two American officers that they were with us. They whispered
with each other and then walked away.
A few minutes later, an officer walked toward us and asked us to follow him. He
said to me, "If you make any moves,l will take you down hard. "
That's when l knew we were actually thought to be doing something terrible. We
were told to sit in a row on the sidewalk, facing the street. I noticed across the street
were our other driver and guards. They were also in a row, but in a kneeling position
with their hands on their heads.
I was shocked. The only explanation could be that our guards had been at the
shooting range in the morning, so the police dog may have picked something up from
that. I also wondered why our Iraqi fellows on the other side of the street were being
treated worse than us when it was our car that was under suspicion(怀疑) .
After the end of the hour long suffering, we were allowed to leave. No longer in
the mood for the party,we all went home.
1. The author and his people were going to the party____.
A. in two cars
B. in one car
C. under the protection of police officers
D. for the purpose of exploding a car
2. The author became aware the situation was worse than expected when__________.
A. they arrived at the checkpoint
B. the officers put their helmets on
C. an officer shouted at him
D. some people were asked to kneel down
3. Paragraphs 6 and 7 are mainly written to_________.
A. analyze the reason for the accident
B. describe the author's terrible feelings
C. state the importance to obey police
D. show how differently the officers treated them
4. The author indicated that in Iraq ,__________.
A. he would think twice before going to social activities
B. it was particularly dangerous for foreigners
C. foreigners were treating local people very cruelly
D. American officers could do whatever they wanted
，内阻
，现在要把它改装成一量程为Um=3
的电压表。
，断开电键S时电表读数U1=
；闭合电键S时电表读数
。试根据他所测出的数据近似计算出这只干电池的电动势E和内电阻
，并说明你所作计算的近似的依据。
和
的大小关系（推进器不在工作状态时）（填“>”、“<”、“=”）
，同步卫星的周期T=8.64×104s。利用以上数据求出卫星在同步轨道上的运动速度（结果保留一位有效数字）
（2）①=（2分）
（2）①（2分）=（2分）理由：两种轨道经过A点受到地球的引力相同，故加速度相同.（说明了万有引力定律和牛顿第二定律更完备）
……（1）
……（2）
（3）
代入数据解得：