题目内容
Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren’t very smooth (光滑的) rub together to make heat energy. The faster you rub two things together, the more friction you can make. Let’s discover friction!
WHAT YOU’LL NEED:
★Soap ★Water ★Your hands
WHAT TO DO:
★Make sure your hands are dry.
★Rub your hands together until you feel the heat of your hands.
★Now, use soap and water to get your hands very slippery (滑的).
★Try to make friction happen while your hands are slippery.
★Please write down what has happened.
LET’S TALK!
Friction is an energy that happens when two things rub together. When friction happens, it makes heat! When your hands are slippery, they won’t make very much friction and your hands won’t get so hot.
DID YOU KNOW?
★Friction happens when you stop your fast running bike.
★Ancient people made fires by rubbing two pieces of wood together. Friction happened though they didn’t know it. ___ __? Friction is everywhere. Have you ever noticed situations where friction is happening? If not, ask your parents to take you out in a car. If it is not hot, touch the tires (轮胎) of the car before and after a short drive to see how much warmer they get from friction.
1.You’d better make your hands ______ to get heat when you rub them.
A. slipperyB. dryC. wet
2.The word “friction” in the first paragraph means “______”.
A. 摩擦B. 震动C. 膨胀
3.We can know from the passage that it’s a ______ experiment.
A. physicsB. chemistryC. biology
4.The topic of the last column (栏目) is ______
A. THINK IT OVER!B. WHAT HAPPENED?C. WORK WITH PARENTS.
5.The main idea of the passage is ______.
A. how to discover frictionB. how to rub your handsC. how to make fires by rubbing
1.B
2.A
3.A
4.C
5.A
【解析】
试题分析：本文是介绍摩擦是怎么产生的，摩擦产生的条件，摩擦产生了什么能量，以及日常生活中一些跟摩擦有关系的现象。
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考点：科普类短文阅读。
