Read the following paragraph and choose the best topic sentence from the four options that follow.
First, there are always customers to be served. I work in a downtown McDonald's that gets lots of traffic, and as soon as I serve one customer, there is always another one ready to order There is constant pressure because I can never step back for a few minutes and relax. Second, I have to put together all of the orders myself. To do that, I have to move all over the serving area： French fries on one side, drinks on the other, and burgers in the middle. I must always move at a fast pace. McDonald's has an image to uphold, and its workers must scurry（小跑）about like ants. Finally, my manager really keeps the pressure on. He watches us like a hawk, and every time I do something wrong, he seems to catch it. He also has a reputation for firing people, and he never lets any of the workers feel that their jobs are safe by the end of the day, I'm emotionally and physically drained, like everyone else, and we all head out the door grumbling