选择自然频率的原则是:要保证正确记录被测电流(电位差)的变化情况,同时又能有效地压制

(A=Kangkang   B=Dad   C=Mom)
A: Dad, could you come and help me?
B: Sure, dear. What is it?
A: I don’t understand the meaning of “interpreter”.
B:  小题1:
A: But I left my dictionary at school.
B:   小题2: 
A: Thanks, Dad, I will. Mom,  小题3: 
C: This word “interpreter” means a person who helps foreigners to translate the language and explain the culture of the country.
A: I see.   小题4: I want to help businessmen all over the world and help them know China.
C: Good idea.   小题5: 

A.What are you doing? B.I want to be an interpreter when I grow up. C.You may go and ask your mother for help. D.You are good at English. E.Oh, dear, you can look it up in your dictionary. F.But you must study English harder than before. G.what does “interpreter” mean in English?