During the day, you spend a lot of time running, jumping, laughing, eating, and talking. You use up a lot of energy(能量) , and by the end of the day you’re tired. Sleep gives your body a chance to rest. But your brain (大脑)and body are not completely at rest during sleep. While you sleep, your mind may think of the things that happened during the day. It keeps the important things in mind as memories(记忆). It also thinks about things you were worrying about, and you may wake up with answers to some of your problems. You also grow while you sleep. The thing called 'human growth hormone (荷尔蒙)' in the body helps you grow during sleep. This growth hormone also helps the body to repair itself. Sleep helps your body to conserve energy too. You use up a lot of energy during your daily activities. But when you sleep, your body temperature falls, and your 'metabolism' (新陈代谢) slows down. You are still using some energy, but much less than when you are awake and active. Have you ever stayed up past your bedtime? Did you have difficulty getting up the next morning? Maybe you had problems seeing clearly or you cannot think clearly. That was your body’s way of saying, 'I need sleep！' A lack ( 缺乏) of sleep can stop your body and mind from working correctly. 小题1:What does 'human growth hormone' do while people sleep? A．It helps people rest well. B．It helps repair the body. C．It helps answer problems. D．It helps slow the body down. 小题2:According to the passage, which of the following tells you need sleep? A．You use up a lot of energy. B．You enjoy daily activities. C．Your body temperature falls. D．You don’t want to get up. 小题3:What does the underlined word 'conserve' mean? A．provide B．move C．save D．spend 小题4:What is this passage mainly about? A．Sleep is very important. B．The brain needs enough sleep. C．Good ways to sleep well. D．People use energy when sleeping