冷铆所用的铆钉由什么钢制成，而且经过什么处理？
参考答案：
用低碳钢制成，经退火处理。
历史上最早从商业银行中分化出来的中央银行是英国的______。
用所给单词的适当形式填空。
1. I warned you _________ (not cross) the street. It's dangerous.
2. She has to avoid _________(eat) fatty (多脂肪的) food.
3. Kangkang didn't notice Hugh _________ (leave).
4. The bus was crowded with _________ (passenger).
5. My English teacher was very _________ (satisfy) with my homework.
