只包含一个频率分量的信号是指什么波？
题型：问答题 简答题
问题：
只包含一个频率分量的信号是指什么波？
题型：问答题 简答题
阅读理解。
Mark is a student. He
is in a good high school. He is fourteen. He's from the U.S.A. He's in Class
One. His telephone number is (010)6357-4219. Joy and Mark are good friends. Joy is thirteen now.
She is in Class Two, Grade One. She is from England. Her telephone number is (010)6357-4321. Joy
and Mark are in the same school, but not in the same class. Their (他们的) English teacher is Miss
Green. Miss Green is from Canada. Her English is good. They like (喜欢) her very much.
根据短文内容，回答下列问题。
1. Is Mark a teacher?
_______________________
2. What class is Mark in?
_______________________
3. How old is Joy?
_______________________
4. Who is their teacher?
_______________________
5. Where is their teacher from?
_______________________