【正文】 刪除：把多余的詞用斜線(xiàn)（ \） 劃掉。s happening？ Salt water is denser than ordinary tap water． The denser the liquid is， the easier it is for an object to float in it． When you lower the egg into the liquid it drops through the normal tap water until it reaches the salt water， at this point the water is dense enough for the egg to float． If you were careful when you added the tap water to the salt water， they will not have mixed， enabling the egg to amazingly float in the middle of the glass． 21． Which of the following is the CORRECT order？ ① Mix in lots of salt． ② Gently lower the egg into the water． ③ Carefully pour in plain water until the glass is nearly full． ④ Pour water into the glass until it is about half full． A．④②①③ B．④①③② C．①④③② D．③④①② 22． What will happen if you drop an egg into a glass of water with about 6 tablespoons of salt？ A． It will float in the water． C． Nothing will happen． B． It will sink to the bottom． D． The result is not known． 23． Why can the egg float in the water according to the passage？ A． Because ordinary tap water is denser than salt water． B． Because ordinary tap water is as dense as salt water． C． Because the denser the liquid is， the easier it is for an object to float in it． D． Because the more the liquid there is， the easier it is for an object to float in it． B Cleaning your plate may not help feed hungry children today, but the timeworn advice of mothers everywhere may help reduce food waste from the farm to the fork, help the environment and make it easier to feed the word’s growing population. Hard data still being collected, but experts in Chicago said about 30% to 50% of the food produced in the world goes uneaten. The average American throws away 33 pounds of food each month— about $40 worth, which means each person throws away almost 400 pounds of food. The US Department of Agriculture says that 23% of eggs and an even higher percentage of produce ends up in the trash. “We fet we have all these fresh fruits and vegetables, and at the end of the week we have to throw them away”, said Esther Gove, a mother of three young children in South Berwick, Maine. “Now, I don’t buy as much fresh produce as I used to.” But the effect of food waste arrives far beyond the kitchen. Agriculture is the world’s largest user of water, a big consumer of energy and chemicals and major emitter of greenhouse gases during production. Experts say reducing waste is a simple way to cut stress on the environment and can ease pressure on farmers, who will be called on to feed an expected 9 billion people around the world in 2050, pared with nearly 7 billion today. No matter how sustainable(可持續(xù)的 ) farming is, if the food’s not getting eaten, it’s not sustainable and it’s not a good use of our resources. In richer nations, fruit and vegetables end up in the trash because they are not pretty enough to meet panies’ standards, have gone bad in a home refrigerator or aren’t eaten at a restaurant. In developing countries, much food spoils before it gets to market due to poor roads and lack of refrigeration. High food prices are another reason, since some people can’t afford the food that’s produced. 24. From the first paragraph, we know that cleaning your plate ____________. A. is your mother’s best advice for you B. can solve certain problems for the world C. can help feed hungry children all over the world D. helps meet the growing population’s needs 25. The underlined word “emitter” in Paragraph 4 means ___________. A. user B. finder C. protector D. producer 26. What is a sustainable and convenient way for a customer in a restaurant? A. Ordering enough and packing the leftovers. B. Ordering more than he or she can eat. C. Ordering less and feeling hungry after leaving. D. Ordering more and leaving the untouched alone. 27. Which of the following topics will follow the text? A. More examples of food waste. B. Experts’ idea on the environment. C. Ways to reduce food waste. D. Advice for food with high prices. C The term“ helicopter parents” refers to“ a style of parents who are over focused on their children” Helicopter parents are always making a big push to provide children with every opportunity to succeed， from baby steps at age 1， homework at age 8， college application at age 18， employment iss