二．判断题（共20分，每空2分） 1.一个系统，状态变量的数目和选取都是惟一的。 （×） 2.传递函数矩阵的描述与状态变量选择无关。 （√） 3.状态方程是矩阵代数方程，输出方程是矩阵微分方程。 （×） 4.对于任意的初始状态和输入向量，系统状态方程的解存在并且惟一

1. 宠物名字
I have a pet _________.
Its/His/Her name is _________.
2. 宠物类型
It/He/She is classified as a/an _________.
3. 宠物食物
It/He/She can eat _________, such as __________________, but_________ is always its/his/ her favorite. So I think it/he/she is a/an _________ animal.
4. 宠物外形及脾性
_________ is (small-sized/medium-sized/large-sized), with _________hair and _________eyes. It/He/She is very _________.
5. 宠物益处
It/He/She can help me __________________. _________ always accompanies me, so I never feel _________.
6. 养宠代价
I love _________ so much that I spend a lot of time on _________ and a lot of money on _________.
7. 疾病预防
I take preventive measures to _________.