参考公式：K²= $\frac{n{\left(ad-bc\right)}^2}{\left(a+b\right)\left(c+d\right)\left(a+c\right)\left(b+d\right)}$ ，其中n=a+b+c+d．

临界值表：

某校七年级学生总人数为800，其男女生所占比例如图所示，则该校七年级男生人数为（　　）

照例句，将下列的句子补充完整。

例句：信赖，往往创造出美好的境界。 

友谊，____ 

口语运用
A: Hi, Tom.
B: Hi, Mary.
A:____ 
B: I’m doing my homework.
A: Do you want to come to my house after school? ____ 
B: That sounds great! ____ 
A: It’s on Long Street. It's a quiet street.
B:____  There is a school on it.
A: Yes, and my house is across from it.____ 
B: OK! I'm sure to see you.
选项：

E.  I know the street.