读短文，选择正确的答案。

      It's Sunday today. It's fine. There are a lot of people in the park. Some girls are flying kites. A young man

is playing balls. Long Long is playing football. I am watching TV in the room. Mei Mei is doing her homework

at home.

1. Is it fine?

A. Yes, it isn't.

B. No, it is.

C. Yes, it is.

2. Who is playing balls? 

A. Long Long.

B. I.

C. A young man.

3. Who's in the park?

A. A lot of people.

B. Some trees.

C. Some boats.

4. What do you do on Sunday?

A. Watch TV.

B. Play computer games.

C. Do homework.

5. Who is flying kites?

A. Long Long.

B. Mei Mei.

C. Some girls.

已知α=(1，k，-2)^T是二次型[*]矩阵A的特征向量，试用正交变换化二次型为标准形，并写出所用坐标变换．