In this circumstance one should revise the hypothesis and develop a new experiment to test it.An example could be the theory of Agraham Gottloeb Werner that all rocks were precipitated from water including not just sedimentary rocks but also volcanic, plutonic and metamorphic rocks. The more the earth was studied, especially by James Hutton in Scotland, the more it became obvious that granites for example were deposited in a molten state, thus disproving that hypothesis or theory.
Development of more railroad systems contributed
most to US westward expansion in the second half of the nineteenth century.
The correct answer between all the choices given is the second choice or
letter B. I am hoping that this answer has satisfied your query and it will be
able to help you in your endeavor, and if you would like, feel free to ask
another question.
The trolleys have been reduced over the last decades, after their initial increase as a public transportation, when new and better ways were discovered/produced for transport, their decline has started.
The buses since their invention, had grown in number and became a very important part of every city's public transportation, and still are.
The rapid transit is the most recent one of the mentioned in here. It's popularity has grown, number increased, and is very practical because it is not causing traffic mess. It is very important transport asset nowadays and makes lives of millions of people much easier.
