中考阅读练习 科技发明类（word版无答案).docx

《中考阅读练习 科技发明类（word版无答案).docx》由会员分享，可在线阅读，更多相关《中考阅读练习 科技发明类（word版无答案).docx（4页珍藏版）》请在得力文库 - 分享文档赚钱的网站上搜索。

1、AIf an elephant used toothpaste, this is probably what itd look like! Learn about chemical reactions by watching this heat-producing mixture bubble and overflow for up to half an hour. Tell your kids that youre going to make some together.What youll need for this project: A two-liter soda bottle, cl

2、eaned Hydrogen peroxide solution（过氧化氢溶液） (at least 6% or greater) Dishwashing soap (liquid) Warm water One yeast(酵母) packet Food coloring A cooking pan (such as for a roast)Directions:1. Place the soda bottle upright in the middle of the cooking pan2. Fill the bottle with a half cup of hydrogen pero

3、xide, a few drops of the food coloring, and a few drops of the dishwashing soap3. In another bowl, mix together two tablespoons of the warm water and the yeast, allowing the yeast to dissolve4. Allow your child to slowly pour the yeast mixture into the soda bottle mixture and watch the elephant toot

4、hpaste come to life1.The main purpose of the text is to .A. give instructions on making elephant toothpaste B. introduce the toothpasteC. show different kinds of toothpaste D.teach kids how to cook2.What ill you need for this project？A. Food coloring B. One yeast(酵母) packetC. A two-liter soda bottle

5、, cleaned D. All of the above3.What does the underlined word “dissolve” probably mean in Chinese?A. 解决B. 溶解C.燃烧 D.发热4.In which section of a newspaper would you probably read the text?A. Sports News. B. Job Wanted.C. Do It Yourself. D. Lost and Found.5.What can you get in the end? A. B. C. D.BMake Ra

6、in Clouds in a BottleFollow these steps to make rain clouds in a bottle!Step1 Fit your cork(瓶塞) to your bottle. You may need to shave the sides off the cork to get a tight fit. Your aim here is the tightest possible seal. Then trim the cork to the length of the bike pump needle. You want the needle

7、to be able to pass through the cork into the bottle, maintaining a tight seal.Step 2 Make a path for the cork, using your fork, drill bit, or needle. Be sure the object you use to pierce(刺穿) the cork is narrower than the bike pump needle, or you wont have a tight seal. When the cork is ready, take i

8、t out of the bottle.Step 3 Pour one teaspoon of rubbing alcohol into the bottle and screw the cap back on.Step 4 With the cap on, turn the bottle horizontal(水平) and roll it so that the alcohol sloshes around and coats the inside of the bottle thoroughly and evenly.Step5 Insert the cork.Step6 Insert

9、the bike pump needle in the cork, then pump the bike pump four or five times. Sometimes when you do this the cork will blow and youll have your reaction. Other times youll have to pump a few times more, then stop and pull the needle out.Youre mimicking(模仿) the part of Earths water cycle in which eva

10、porated water (水蒸气) cools and condenses, forming clouds as they connect with dust. In this experiment, the alcohol acts like the dust, providing something cool for water droplets to attach to.When you pressurize the soda bottle by pumping air in, the air molecules(分子) collide with each other and war

11、m the bottle. Releasing the pressure causes the water vapor to condense quickly, forming a cloud.1.How many steps do you need in this experiment?A. 4 B. 5 C. 6 D. 72.They can be used to make a path for the cork except_.A.fork B.chopstick C.drill bit D.needle3.Which picture can describe “step 6”?A. B

12、. C. D. 4.What does the underlined word “pressurize” probably mean in Chinese?A.倒入 B.缓解 C.增压 D.打开5.In which section of a website would you probably read the text?A. Sports B. ArtsC. Science D. AnimalsCMake Ice CreamChill out with this easy recipe for a DIY treat.Milk is a complicated mixture of lots

13、 of different kinds of molecules(分子), including fats, proteins, and water. 1 The trick to making ice cream is to get the cream cold enough to freeze without the parts separating. The success of this recipe comes down to keeping it all moving. 2 You Will Need2 quart-size plastic bags1 gallon-size pla

14、stic baga dish towel cup heavy cream cup whole milk tsp. vanilla extract1 Tbsp. sugar4 cups crushed ice4 Tbsp. rock saltStep 1Put the cream, milk, vanilla, and sugar in one qt.-size plastic bag. Remove as much air as possible and seal the bag well. Put this bag inside the second qt.-size bag, again

15、removing as much air as possible and sealing it well. (Double- bagging the ice cream mixture will help to prevent leakage.)Step 2Put the double-bagged mixture into the gallon-size plastic bag and add the ice and salt. Once again, remove as much air as possible from the bag and seal it well.Step 3Wra

16、p the bag in the dish towel. 3 Keep massaging it for 58 minutes. Open the bag. Inside, the mixture will have frozen into ice cream!THE SCIENCE SCOOPWhen water molecules freeze, they line up in a neat, orderly, and tight formation, 4 If you just put your ingredients in the freezer, the water molecule

17、s would separate out as large chunks of ice. But when you toss and shake the molecules in the bag, they cant connect or easily get a grip on one another. Only microscopic chunks of ice are able to form, keeping the water mixed in with everything else. Its hard for water to freeze when there are othe

18、r molecules in the way, so the temperature has to be colder than that for making regular ice for it to happen. Thats where your outer bag of ice and salt comes in. 5 A.so theres not much room for other molecules to mix in. B.Get ready to shake your way to dessert!C.Salt lowers the temperature of the ice so that your ice cream mix is cold enough to freeze. Shake D.and massage the bag, ensuring that the inner bag is surrounded by the ice. E.Normally, freezing would cause milk to separate into its various parts.