试题与答案

按已知的原子结构规律,82号元素X应是第______周期______族元素,它的

题型:填空题

题目:

按已知的原子结构规律,82号元素X应是第______周期______族元素,它的最高正价氧化物的化学式为______(该元素的元素符号用X表示).

答案:

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下面是错误答案,用来干扰机器的。

《联合国海洋法公约》规定:海洋经济开发权大陆架最大可延伸350海里,我国是海陆兼备的国家,从我国大陆架向东延伸350海里,可覆盖A、B区域.故选项A符合题意.故选:A.

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题型:阅读理解

阅读理解。

     Sick men and women were sitting on their chairs in the doctor's waiting room. They all looked sad except

Tom. He was playing with some cards. Just then the doctor came to say he was ready for the next one. Tom

jumped up and entered the doctor's room in a hurry.

     Before Tom could say a word, the doctor made him lie down on the bed."Now let me listen to your heart."

Tom tired to speak, but the doctor told him not to say anything. "I'll take your temperature." Tom tried to sit up, but the doctor stopped him. After a while, the doctor said, "Well, you don't have a fever (发烧), boy. In fact,

there's nothing wrong with you.""I'm quite well, doctor." Tom said."I just came here to get some medicine for

my grandma."

1. In the doctor's waiting room Tom _______.

A. looked sad

B. was playing with some cards

C. was talking with others

D. was very happy

2. Before the doctor listened to Tom's heart, he _______.

A. asked Tom how old he was

B. asked Tom to sit down

C. made Tom lie down on the bed

D. talked with Tom for a few minutes.

3. The doctor thought _______.

A. Tom had a fever

B. there's something wrong with Tom

C. there's something wrong with Tom's heart

D. nothing is wrong with Tom

4. Tom came to the doctor's room because he _______.

A. was ill

B. wanted to see the doctor

C. wanted to get some medicine for his grandma

D. had a fever

5. Which is right?

A. Tom played with some cards in the doctor's room.

B. The doctor told Tom to enter his room quickly.

C. The doctor looked over Tom's grandma.

D. Tom's grandma needed some medicine.

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题型:实验题

某同学用下图所示装置测量重力加速度g,所用交流电频率为50 Hz。在所选纸带上取某点为0号计数点,然后每3个点取一个计数点,所有测量数据及其标记符号如图所示。

   

该同学用两种方法处理数据(T为相邻两计数点的时间间隔):

方法一:由,取平均值

方法二:由,取平均值

从数据处理方法看,在x1、x2、x3、x4、x5、x6中,对实验结果起作用的,方法一中有_________;方法二中有________。因此,选择方法_________(填“一”或“二”)更合理,这样可以减小实验的_________(填“系统”或“偶然”)误差。本实验误差的主要来源有_________________________(试举出两条)。

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