题目

用方框中所给单词的适当形式填空，使对话通顺、正确，每词仅用一次(每空一词)。 electricity new if beautiful invent A: What's that, Nick? B: Oh, it's my , Come and look at it, Bob.A: Is it a model(模型) car? B: Yes, and it's a clean car.A: It's , How does it go? B: It uses sunlight or .A: That's great. The air would be clean all the cars were like it.B: You're right, Bob.A: Could you make one for me, Nick? B: Sure. You'll have a one next Monday.A: Thank you.如图所示电路，D1、D2是两个相同的小灯，L是一个自感系数很大的铁芯线圈，其电阻与R相同．由于存在自感现象，在电键S接通和断开时，D1、D2先后亮暗的次序是（　　）A．接通时，D1先达最亮；断开时，D1后熄灭B．接通时，D2先达最亮；断开时，D2后熄灭C．接通时，D1先达最亮；断开时，D1先熄灭D．接通时，D2先达最亮；断开时，D2先熄灭