正弦交流电在变化的过程中，有效值也发生变化。( )
参考答案：对
句型转换。
1. I'm a teacher. (改为一般疑问句)
_____ _____ a teacher?
2. I'm from England. (对划线部分提问)
_____ are you _____ ?
3. My son is eleven years old. (对划线部分提问)
_____ _____ is your son?
4. Tom is an English boy. (改为否定句)
Tom _____ _____ an English boy.
5. are, friends, good, Tony, I, and (. ) (连词成句)
___________________________
语言艺术有哪些特点？
