若加在二极管上的反向电压超过击穿电压值，则二极管会损坏。
查看答案
二极管导通后的管压降很小，硅管约为0.7V。
A. 对
B. 错
Listen to the customer enquiries below that take place at a checkout area. Read the three possible cashier responses for each enquiry. Which is the correct response? Choose your answers.1. Customer:Cashier:[音频]
A. I'll put them back on the racks for you. Sorry they didn't fit.
B. I'm sorry, we only accept cash or credit card.
C. Sure, we can hold them for you for three days.
2. Customer:Cashier:[音频]
A. Sure. They're $50 regular. So today they're $25.
B. Please grab a pair from the shelf that has a price sticker.
C. No you don't have to buy both pairs to get the discount.
3. Customer:Cashier:[音频]
A. I'm glad you enjoyed your stay. Come again.
B. Sure, I'll call for assistance. It will just take a moment.
C. Yes, you can purchase most things here.
微信支付 
支付宝支付