Which of the following sentences has mixed verb tenses (and is therefore incorrect)

What caused the american civil war? there were many reasons for a civil war to happen in america, and political issues and disagreements began soon after the american revolution ended in 1782. between the years 1800 and 1860, arguments between the north and south grew more intense. one of the main quarrels was about taxes paid on goods brought into this country from foreign countries. this tax was called a tariff. southerners felt these tariffs were unfair and aimed toward them because they imported a wider variety of goods than most northern people. taxes were also placed on many southern goods that were shipped to foreign countries, an expense that was not always applied to northern goods of equal value. an awkward economic structure allowed states and private transportation companies to do this, which also affected southern banks that found themselves paying higher interest rates on loans made with banks in the north. the situation grew worse after several “panics,” including one in 1857 that affected more northern banks than southern. southern financiers found themselves burdened with high payments just to save northern banks that had suffered financial losses through poor investment. which sentence from the selection states a major detail that supports the main idea? a there were many reasons for a civil war to happen in america, and political issues and disagreements began soon after the american revolution ended in 1782. b taxes were also placed on many southern goods that were shipped to foreign countries, an expense that was not always applied to northern goods of equal value. c the situation grew worse after several "panics," including one in 1857 that affected more northern banks than southern. d this tax was called a tariff. e between the years 1800 and 1860, arguments between the north and south grew more intense.

Which change should be made to improve this sentence? allen jumped in the puddle and his new shoes got wet and muddy. a)the new shoes got wet and muddy and allen jumps in the puddle. b)allen jumped in the puddle and got his new shoes wet and muddy. c)allen jumped in the puddle and gets his new shoes wet and muddy. d)the new shoes are getting wet and muddy and allen jumped in the puddle.

How are the two arguments made in the passages different? a. the first passage claims that pets in class will children with health problems; the second passage says pets will make some health problems worse. b. the first passage claims that students’ nervousness will decrease around pets; the second says that students’ nervousness will increase around pets. c. the first passage claims that pets will make the teacher’s work easier by keeping students busy; the second passage says pets will make the teacher’s work harder. d. the first passage claims that pets in school will be good for kids’ mental health; the second passage says pets will be bad for kids’ mental health.