“一手交钱,一手交货”是商流和物流统一的交易形式。
参考答案:对
某品牌家用电熨斗的电路如图甲所示,额定电压为220V 、最大功率为440W ,发热部分由调温电阻R和定值电阻R0组成,调温电阻R是可变电阻,其最大阻值为110Ω。电阻值均不受温度影响。
(1)定值电阻R0的阻值是多大?
(2)该电熨斗工作时的最小功率多大?此时通过电路的电流是多大?
(3)假设电熨斗每秒钟散发的热量Q跟电熨斗温度t的关系如图乙所示,请分析得出电熨斗工作时温度的调节范围。
用括号内所给词的正确形式填空。
1. Most _______ (busy) letters are written in English.
2. Project hope is an _______ (organize) that helps children go to school.
3. He is one of _______ (famous) actors in our country.
4. The principle will give us a _______ (speak) tomorrow afternoon.
5. There will be a musical _______ (perform) in the show.
6. The girl often give out leaflets _______ (ask) people to donate money.
7. It was my job _______ (introduce) each star.
8. I _______ (help) with a charity show this time last week.
9. This is the best model I _______ ever _______ (see) .
10. I hear the show _______ (hold) in a middle school next week.
11. A new bridge_______ (build) in my hometown last year.
12. I hope _______ (be) a doctor after I know something about ORBIS .