The key answer of exercise 4

Both bakers and firefighters have interesting jobs, but their jobs differ in many ways. To start with, a baker's job is not as dangerous. Whereas, a firefighter's job is hazardous and risky. Although once mastered there are no new skills to be learned being a baker , working as a firefighter requires constant training. Also, a baker has a happy work environment whereas a firefighter can witness people getting hurt. In addition, a baker must work long hours every day compared to a firefighter, who does shift work. Also, a firefighter has financial security because he gets paid well. A baker, on the other hand, can be poorly-paid.