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.

下列各句中划线成语的使用，全都正确的一项是（    ）

①与做人一样，李天来对待试验同样谨小慎微。他说：“试验处理获得的数据是要用来指导生产的，不能有‘差不多’等情况出现。”

②我国反导技术研究尚处于起步阶段，还不能与美国的反导技术相提并论。未来我国的反导系统将部署于国内，用于担负本土防御任务。

③当前，超级计算机的应用方兴未艾，其应用涉及许多前沿领域，如IBM的超级计算机“蓝色基因”正在尝试复制人类意识。

④豪斯德尔集成墙板，以其对市场独到的见解和对欧洲家居装饰市场的潮流把握，将环保、时尚、实用集于一种产品之上，投资者趋之若骛。

⑤“人命至重，有贵千金”，在突发疾病、意外伤害面前，分分秒秒都生死攸关。救人性命是人的本能，但人们又常常会束手待毙。

⑥美术设计是仁者见仁的事，不可能强求同一标准。美学本身没有同一标准，浙江大学对校门设计的不同意见不妨择其善者而从之。

学习科学需掌握一定的科学方法，明确实验原理及并能对结论进行科学推理．

（1）我们在科学实验时，为了减小误差或寻找普遍规律，经常需要进行反复多次实验．

①“测量物体的长度”时，多次测量；

②“研究杠杆的平衡”时，改变动力（臂）和阻力（臂），多次测量；

③“研究串、并联电路的电流特点”时，换用不同定值电阻，多次测量；

④“用电压表和电流表测导体的电阻”时，多次测量电阻两端电压和通过电阻的电流值；

上述实验中寻找普遍规律的是​ ____