【正文】 —OK. I will practice more. A. if B. but C. because D. unless D D 四、閱讀理解 One of the easiest and cheapest ways to help your health is just to sleep eight hours or more every night, but more and more people in the world are not sleeping enough. According to the World Health Organization, over half the people in the world may be sleepdeprived. The result of this is not just a lot of tired people. In the United States alone, sleepy drivers cause at least 100,000 car accidents, and 1,500 deaths a year. Problems with sleep can also cause mental (心理的 ) problems, as well as medical problems such as high blood pressure and heart problems. American culture values work and often doesn’t value sleep. In fact, people who sleep a lot are often called “l(fā)azy”. Many famous men say proudly, “I only have time to sleep four or five hours a night.” Students, especially college students, often sleep only a few hours a night. They often say, “I’m used to sleeping only a little.” But according to experts, sleep is like money. If you sleep only five hours a day, you don’t “get used to it”, but instead, build up a “sleep deficit (虧損 )”. “It’s like a credit card (a card used to buy things or services), ” says Dr. James Maas.“You are only borrowing time. Y