根据短文内容，选择最佳答案。

     We go to school at seven thirty. Our classroom is behind the trees. It's very nice. There is a map of

China on the wall. Twenty boys and fifteen girls are in the classroom. There are some flowers on the

teacher's desk. They are for our teachers. We have four classes in the morning and two in the afternoon.

We aren't at school on the weekend.

1. We go to school at              .

A. 7:13                      

B. 7:03                  

C. 7:30

2. Our classroom is               some trees.

A. behind          

B. in                      

C. under

3. A map of China is on the _            .

A. desk            

B. wall                    

C. blackboard

4. The _             are for the teachers.

A. maps            

B. desks                          

C. flowers

5. There are                 students in our ciass.

A. forty-five                  

B. fifteen            

C. thirty-five

如图所示，对氯原子和氯离子的认识中，不正确的是（　　）

A．它们的质子数相同

B．它们的电子数相同

C．氯离子的最外电子层是相对稳定结构

D．它们的电子层数相同