阅读短文判断正误，正确写T，错误写F，

     Our school is very big and nice. In our classroom, there are some maps and pictures on the

wall. There is a nice clock on the front wall. There is a TV set in front of the room. There are many desks

and chairs in the room. Outside the rooms, we have a big playground. We can play soccer, basketball, and

any sports we like. We clean the school every day. We think it's very happy to study in the clean place.

( )1. The school is big and dirty (脏的).

( )2. There is a nice clock on the back wall.

(     )3. There is a TV set in front of the room.

( )4. Every day the students clean the school.

( )5. We think it's happy to study in the clean place.

伽马刀治疗的主要优点是()

A．无手术创伤

B．对病灶周围正常组织损伤小

C．治疗疗程较短

D．价格便宜

E．以上都不是