从自动控制原理的观点看,家用电冰箱工作时,房间的室温应为()
A.给定量(或参考输入量)
B.输出量(或被控制量)
C.反馈量
D.干扰量
参考答案:D
Read and choose. (读短文,回答下列问题)
Good morning, everyone. I'm Sarah. I'm from Canada. That is my family. My mother is beautiful.
She is drinking some tea. That's my father. He is very smart. He is drawing a duck. Who's that boy?
Oh, that is my brother, Joe. He is a student. He is singing and dancing now.
1. 一 Where is Sarah from?
一 She is from _____.
A. China
B. America
C. Canada
2. 一 How many people are there in Sarach's family?
一 _____.
A. Two
B. Three
C. Four
3. 一 Is Sarah's mother beautiful?
一_____.
A. Yes, she is
B. No, she isn't
C. We don't know
4. Sarah's father is _____.
A. drawing a duck
B. drinking some tea
C. singing and dancing
5. Sarah's brother is a _____.
A. teacher
B. student
C. girl
A.电池a的电动势较大,内电阻较小
B.电池b的电动势较大,内电阻较大
C.电池b的电动势较小,内电阻较大
D.电池a的电动势较大,内电阻较大