问题 单项选择题

PNa测定中的加碱过程至关重要,尤其在线仪表连续测量时,碱试剂添加方法不当,会造成加碱不均匀和(),致使仪器产生误差,甚至不能正常工作。

A、反应缓慢

B、样品温度变化

C、样品受到污染

D、不稳定

答案

参考答案:D

阅读理解

阅读理解。

Here is some news from Dalian Daily.

·President's pet.

     Do you keep a pet? American President Obama does.He calls his new dog Bo.It is six months

 old.The president's family like the dog very much.Look! They are having fun with Bo on the South

Lawn (南草坪)of the White House.The president's daughter, Malia ,is showing the dog off.

·Back on her feet.

     Mosha is a young elephant in Thailand.She lost her right front leg after stepping on a landmine(地雷)

two years ago.She was taken to a hospital and became the first elephant in the world with a prosthetic leg

(假肢).

     Now aged three Mosha is growing up.She is happy to have the new prosthetic leg.

·Liu Xiang

     World champion Liu Xiang returned to Shanghai on March 8.The 25-year -old star had a foot

operation in December in America.It took him three months to recover(康复)and train there.It is

said that some doctors are ready in Shanghai to help with Liu's recovery.Liu left the 2008 Beijing

Olympics because of his foot injury(损伤)last August.

1.The name of the president's dog is          .

A.Washington    

B.Bo    

C.Malia          

D.Obama 

2.How old is the dog?

A.Two months old  

B.Three years old  

C.Six months old  

D.Six years old

3.How did the elephant lose his front leg?

A.She had a traffic accident.        

B.She stepped on the landmine.

C.She was ill.                    

D.She fell into a big hole.

4.Liu Xiang had his foot operation in         .

A.China          

B.America        

C.Japan          

D.Australia

5.Liu Xiang left the Beijing Olympics because       

A.he was afraid of the other players      

B.he was too nervous to take part in it

C.his coach told him to do that          

D.his foot hurt

问答题 简答题