1. Iron and steel, automobile, coal, light industry, high-tech Fushun Fuxin coal and iron resources are abundant, plus early development factors.

2. What is divisible by 45 can also be divisible by 9 and 5.

Let's count first, 817-27 9-913 = 914-(9 * 3) 9-913 = 914-9 9 * 3.

The results show that 9 13 is definitely divisible by 9, while the prefix 5 is divisible by 5, so the number can be divisible by 45.

3. Breaking the material structure (promoting solution mixing) and passing through obstacles (seeing through the human body)