独立需求是指某产品或服务的需求与其他产品没有关联，是完全独立的。其数量与需求出现的概率是随机的，不确定的。
参考答案：对
用所给词的正确形式填空。
1. Amy is from England. She is ________. (England)
2. ________ (Canada) speak English and ________ (France).
3. Jim's parents _________ (not watch) TV on Sundays.
4. I ________ (not watch) TV now.
5. Look! Somebody _________ (swim) in the river.
6. They like _________ (play) football on weekends.
7. Kate often _________ (help) me ________ (clean) the house.
8. My sister _________ (put) on her coat now.
9. It's 8:00 in the evening. We _________ (watch) TV.
10. Listen! Tom _________ (not read). He _________ (sing).
热电偶的热电势的大小与（）有关。
A、组成热电偶的材料
B、热电偶丝的长度
C、组成热电偶的材料和两端温度
D、热电偶丝的粗细
