家用电饭锅有两种工作状态，一是锅内水烧干前的加热状态，一是水烧干后的保温状态，其电路如图所示，R1是一电阻，R2是加热用的电阻丝，则电饭锅
A．S闭合为保温状态
B．S断开是加热状态
C．S闭合为加热状态
D．S断开是保温状态
CD
题目分析：S闭合时，R1被断路，R2中的电流较大，热功率较大，处于加热状态，S断开时，R1与R2串联，R2中的电流较小，热功率较小，处于是保温状态，AB错误，CD正确。
用方框中所给单词的适当形式填空，使短文通顺、正确、连贯（每个单词限用一次）
To: Christin foo@hotmail.com Date: 23rd March Subject: The Riding for the Disabled Association Hi Christine, Sorry I haven’t emailed lately —I’ve been very busy since becoming a volunteer for the Riding for the Disabled Association. Every Saturday, I help to get the horses 小题1:___________ for the disabled(残疾) riders. Many more disabled people want to ride 小题2:___________ than you’d imagine. It’s a disadvantage that I don’t know how to ride —I’d love to got on long rides with the riders— but I’ll learn soon 小题3:___________. Right now, I’m just happy to be able to lead the horses around for the disabled riders. I’m小题4:___________ helping to organize a sale, which will be 小题5:___________ next month. It’s a lot more work than helping the disabled. I need to collect second-hand things to sell at the sale. There are 小题6:___________ things available(获得的) than I thought, but I’m sure we’ll have enough小题7:__________ next month. I hope the sale raises more money than last month’s walk. It was rainy, so too few people took part in the event. Last week, we held an auction(拍卖). The auction took much less 小题8:__________ to organize than the walk. 小题9:__________, for some reason, people offered too little money for the things, so we didn’t raise enough money. I’m 小题10:___________ you some pictures in the letter, as well as a speech I gave last week. |