有关酶Km值的叙述正确的是Km值（）。A．是酶-底物复合物的解离常数 B．与酶的结构

阅读理解。

     Mr. and Mrs. Clarke were going to America for their holidays. They had a dog called Billy.

They liked him very much. But they couldn't take him to America with them. So they found a place

to leave him while they were away. At the end of their holidays they got back to England very late

at night so they didn't go to get Billy. The next morning Mr. Clarke got into his car and drove happily

to get Billy. When he got home with the dog he said to his wife, "Dear, I don't think Billy has enjoyed

his days at that place. He made lots of noise all the way home. I guess he must want to tell me

something!" Mrs. Clarke looked at the dog carefully and answered, " You are quite right, dear, but

he wasn't trying to tell you he hadn't enjoyed his day at that place. He was trying to tell you that you

had brought the wrong dog home. That isn't our Billy."

1. Mr. and Mrs. Clarke were going to America_____.

A. to meet their friends    

B. to see their family    

C. to spend their holiday

2. Mr. Clarke drove to get Billy back______.

A. as soon as they came back

B. late at night

C. the next morning

3. Mr. Clarke thought that Billy ____ at that place.

A. had a good time.  

B. didn't have a good time  

C. liked to made noise

4. Mrs. Clarke found that ____.

A. her husband was quite right.  

B. the dog was Billy  

C. her husband had brought the wrong dog home.

5. Which of the following is right?

A. Mr. and Mrs. Clarke loved Billy very much.

B. Billy really enjoyed himself while they were away.  

C. Mr. Clarke brought their own dog home.

读下面四省（区）轮廓图，回答：

（1）写出四省简称及行政中心：

    A ____________，___________； B ____________，___________；

    C ____________，___________； D ____________，___________。

（2）黑河—腾冲是我国人口分布的地理分界线，该线反映了我国人口分布的基本特点，那就是此线以

    东，人口________；此线以西，人口________。四省（区）中位于该线的东北端点的是_________省。

    安徽省位于该线的________方。 

（3）四省中有少数民族数目最多的是_________省，其中有泼水节的少数民族________族。

痢疾杆菌最常侵犯的部位是（）

A.升结肠

B.直肠和乙状结肠

C.横结肠

D.升结肠和横结肠

E.小肠

纬二重组织是由两个或两个以上的纬纱与（）交织而成的。

制备成的分析试样，其最大试样粒度不超过02毫米。