What does the word "they" in the second paragraph refer to?

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.

I don’t know much about computer, so I asked the assistant for____________advice.

You should know that everyone in this office____________busy planning the dance for a week.

Everyone thought she would accept the offer. ____________, she turned it down immediately.

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Keith had so interesting and creative plans that everyone wanted to work on his committee.

It was hard to____________the temptation to watch the late-night show even though I was so tired then.

Even though she had been studying hard, she had only a____________chance of passing the exam.

The company managed to beat the ____________on delivering its new system.

Most headaches____________with aspirin unless they are too severe.

I would have cooked something special if I____________you were coming.

Women have proved repeatedly that they are equal and often superior____________men in almost every field.

Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks from 33 to 37.

Everyone wants to reduce pollution. But the pollution (33) ____________is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. (34) ____________, exhaust from automobiles causes a large percentage of air pollution. But the automobile provides transportation for millions of people. Factories discharge much of the material that pollutes the air and water but factories give (35) ____________to a large number of people.

Thus, to end or greatly reduce pollution immediately, people would have to (36)  ____________using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws (37) ____________require businesses and traffic to stop, or to cut down on certain polluting activities.

Amy and Jacob are talking about the two-day excursion at the end of the school year. Amy: “You look so sad. ____________”

Jacob: “I couldn’t get my parents’ permission to stay the night away from home.”