完形填空

　　Sometimes you may envy(妒忌)others when they do a 　　1　　 job than you．It is not strange．If you treat envy in a right way, it can 　　2　　 you to move ahead．But if you are always 　　3　　 others, then it is 　　4　　, because much envy may make you 　　5　　 your own life in the end and you have 　　6　　 time to do something you are good at．

　　　　7　　 do you waste time to envy others?Envy itself can change 　　8　　．Why not spend more time and try your best to 　　9　　 others?It is up to you．

　　Of course, it is easier said than 　　10　　．Maybe you hope not to envy others, but you 　　11　　 how to do it．Maybe you tried many times but 　　12　　 failed．Please don’t lose heart．Set a goal for 　　13　　, and work hard to realize it．Then you have no time to envy others．When you 　　14　　, you don’t need to envy others any more．Isn’t it true?Believe yourself, it is also very 　　15　　 to you．

阅读理解

　　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 rub together to make heat energy．The faster you rub two things together, the more friction(and heat)you can make．Let’s discover friction!

　　WHAT YOU’LL NEED：

　　●Soap　　●Water　　●Your hands!

　　WHAT TO DO：

　　1．Make sure your hands are dry．

　　2．Rub your hands together until you feel the heat of your hands．

　　3．Now, use soap and water to get your hands very slippery(滑的)．

　　4．Try to make friction happen while your hands are slippery．

　　5．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?

　　1．Friction happens when you stop your fast running bike．

　　2．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 too hot, touch the tires(轮胎)of the car before and after a short drive to see how much warmer they get from friction．