不属于鸟氨酸循环中间产物的是（）A、精氨酸 B、瓜氨酸 C、精氨酸代琥珀酸 D、延胡

阅读理解。

     At May Middle School in London, the students must stay at school from Monday to Friday. They

can go into the town in the evening , but must return to the school before eight o’clock.

     A student called Bob walked to the town and went to the cinema. When he arrived at school, it was

half past eight. He was a little worried. He ran quickly to the gate. It was closed too. Then he saw an

open window on the first floor. It was the headmaster’s office. Bob looked into the room. No one was

there. He quickly climbed up and jumped into the room, just then he heard someone was talking outside

the door. He looked around and hid himself under the sofa. One minute later, the headmaster came in .

He turned on the light and sat on the sofa. Then he began to read.

     Bob lay under the sofa and looked at the headmaster’s feet for an hour. He was too afraid to move.

Finally the headmaster stood up and walked towards the door. ‘Thank Goodness, he did not find me

under the sofa,’ thought Bob. Then the headmaster stopped. He turned his head and spoke to the sofa,

"Could you turn off the light before you leave?" and then left the office.

1. May Middle School _____________.

A. had its own cincema      

B. was in the centre of the town

C. was not in the town      

D. did not have students in the evening

2. Why did Bob come back late one day?

A. His watch didn’t work.    

B. He enjoyed himself in the cinema.

C. He walked slowly.        

D. There was no bus to his school.

3. The headmaster’s office _______________.

A. was on the ground floor    

B. was near the gate

C. was not on the ground      

D. was always open in the evening

4. How long did Bob stay in the headmaster’s office?

A. For half an hour.          

B. For nealy an hour.

C. For less than an hour.      

D. For over an hour.

5. Which of the following is not true?

A. Bob went into the school building through the gate.

B. The headmaster might see Bob’s feet when he did his reading.

C. Bob kept himself under the sofa before the headmaster left.

D. The headmaster knew someone else was in his office.

以下关于俄罗斯的叙述，错误的是[ ]

A．首都莫斯科位于亚洲

B．俄罗斯人占总人口的83%

C．俄罗斯人口超过1亿

D．大部分地形比较平坦，平原和高原面积广大

用如图甲所示的实验装置做“研究平抛物体的运动”实验．

（1）对于实验的操作要求，下列说法正确的是______

A．应使小球每次从斜槽上相同的位置自由滚下

B．斜槽轨道必须光滑

C．斜槽轨道末端可以不水平

D．要使描出的轨迹更好地反映真实运动，记录的点应适当多一些

（2）根据实验结果在坐标纸上描出了小球水平抛出后的运动轨迹．部分运动轨迹如图乙所示．图中水平方向与竖直方向每小格的长度均为l，P₁、P₂和P₃是轨迹图线上的3个点，P₁和P₂、P₂和P₃之间的水平距离相等．若已测知抛出后小球在水平方向上做匀速运动，重力加速度为g．可求出小球从P₁运动到P₂所用的时间为______，小球抛出后的水平速度为______．

在一个V升的密闭容器中放入2L A气体和1L B气体，在一定条件下发生反应：

3A（g）+ B（g）=nC（g） + 2D（g），达到平衡后，A的浓度减小，混合气体的平均分子量增大，则该反应方程式中n值是

A．1

B．2

C．3

D．4