1.) B . the internal combustion
The internal combustion make it possible for vehicles to create small controlled explosion that can be use to generate force that move the vehicles forward. The develoment of internal combustion was the one that make cars able to move fast without having to burn all of the gas in one motion.
2.) D . medicine advanced, and the death rate fell
The advancement in medicine and lesser amount of wars made European population able avoid death at young age and to survive different type of diseases that considered as lethal in the previous time period. Both of these changes make the life expectancy of European people surpass 60 years odl.
3.) D . to improve their working conditions
There are some corporations that have the intention to exploit their employees by giving unfair salary and unreasonable working horus. Because of this, some workers organize unions in order to put pressure to business owners to sit together with their representative and find a common ground.
4.) A . disease spread quickly due to poor medical care
During the second phase of the industrial revolution, large number of workers were overworked by the companies without receiving any medical insurance. Because of this, their immune system dropped and disease spread quickly among the workers.
5.) B . the first made great strides in medicine while the second one focused more on building factories
The first industrial revolution put more emphasis on invention while the second industrial revolution put more emphasis on maximizing production output. Becaue of this, majority of the industrialization occurs on manufacturing sectors rather than stem field.
6.) C . he identified the microbe that caused tuberculosis, a very dangerous disease
At that time, tuberculosis was a very common disease among workers that constantly exposed to indoor air pollution, Identifying the microbe was a very important achievement because it allows the scientist after him develop the proper medicine to handles the infection,
7.) A . where workers were initially the most powerful force in society, big business consolidated power in management
By consolidating power in management, the businesses able to obtain deeper control over its employees which allow them to make demands and impose regulations to the employees. Because many businesses abuse this power, Union workers started to develop at the same time period.
8.) C . people moved to small towns because they could visit the city by train
Before trains exist, people have to leave in the location that is near from their working place. After the development of train, people could choose to live in the suburbs that far away from their working location and can still managed to get into their office on time every day,
9.) D . the increase popularity of single-family homes among the lower classes
The increasing popularity of the single-family holmes increase the needs to create more property units that take up a lot of space within the city. Because of this, apartements started to became popular and small business establishments that cater to fulfill people's daily needs (such as diners or barbershops) started to developed around the neighborhood.