铁和钢都是铁碳合金,一般碳含量大于1.7%的叫生铁,碳含量0.2%~1.7%的叫钢。
参考答案:对
根据汉语提示填空。
1. He didn't pass the exam. He looks ______ (不高兴).
2. "Gardon" is an ______ (不正确) spelling. It must be"garden"
3. It's not good to be an ______ (不诚实) boy.
4. He broke his leg yesterday. He is ______ (不能) to take part in the sports meeting.
5. Nothing is ______ (不可能) if we put our hearts into it.
6. He thinks it ______ (没有必要) to brush the teeth twice a day.
平巷信号把钩工如有挂不上钩时,()蹬钩作业。
A.严禁
B.可以
C.有时