The key answer of exercise 8

a)

Paragraph 1

1. One of the best decisions I ever made was to go back to school.
2. Before that, I was working for a company, but I didn't enjoy my job.
3. I've always thought that being a teacher would be really interesting.
4. So | went back to college and did a teacher training course.

Paragraph 2

1. Doing the course wasn’t easy.
2. For example, I had to work to earn money, and find time to do coursework.
3. So l used to study in the evenings.
4. Now, I have a teaching qualification, and I'm doing the job l've always wanted to do.

b)

In each paragraph:

1. Sentence 1 contains the main idea.
2. Sentences 2 and 3 support the idea.
3. Sentence 4 finishes / concludes the paragraph.