The second industrial revolution; unit 3 lesson 2 of honors world history b

1. In my view the internal combustion engine had the greatest impact on transportation during the second industrial revolution. It had a good perspective in future. 

2. I agree with your choice "medicine advanced, and the death rate fell". The factors like hygiene, good sanitation and improved medicine caused population growth between 1800 and 1900.

3. This one is correct. Unions was the perfect way to improve working conditions. Workers' unions had a great influence as human labour wasn't fully replaced and it was a good idea to invest money in good working conditions. Better conditions = better work.

4. Edison's inventions changed the world. And I think that your answer is correct. As it's the most suitable answer from given above. The structure of society has changed as this invention allowed factories and other businesses work all night long. It's really huge profit.

5. I think this one is wrong. If my memory serves me well  "disease spread quickly due to poor medical care" is about first industrial revolution. This one is correct: new sewer systems decreased death rates

6.  In my opinion correct answer is: the first used iron as the primary metal for industry while the second one used steel. Products and its manufacturing is the main difference between these two. Iron, coal and clothes were in first; steel, petroleum and electricity was in the second.

7. Yes, your answer is correct. Joseph Lister was the first who introduced the process of antiseptic. Death was dramatically decreased because of this process. Also sanitation was improved because of that.

8. And again you're correct. "the increasing need for skilled labor made it necessary for big business to listen to the demands of workers" - this is why workers unions had occurred.

9. This one is also 100% correct. "Cities grew rapidly as people moved from rural areas to work in the industry" - it was the main trend during the second industrial revolution. This process is called urbanization if I'm not mistaken.

10. In my view correct answer is this: "The desire of middle class for parks, department stores, and wider streets."  Urbanization caused huge population of middle class.