Although April did not bring us the rains we all hoped for, and although the Central Valley doesn't generally experience the sound and lightning that can go with those rains, it's still important for parents to be able to answer the youthful questions about thunder and lightning. The reason these two wonders of nature are so difficult for many adults to explain to children is that they are not very well understood by adults themselves. For example, did you know that the lightning we see flashing down to the earth from a cloud is actually flashing up to a cloud from the earth? Our eyes trick us into thinking we see a downward motion when it's actually the other way around. But then, if we believed only what we think and we see, we'd still insist that the sun rises in the morning and sets at night. Most lightning flashes take place inside a cloud, and only a few can be seen jumping between two clouds or between earth and a cloud. But, with about 2,000 thunderstorms taking place above the earth every minute of the day and night, there's enough _ to produce about 100 lightning strikes on earth every second. Parents can use thunder and lightning to help their children learn more about the world around them. When children understand that the light of the lightning flashing reaches their eyes almost at the same moment, but the sound of the thunder takes about 5 seconds to travel just one mile, they can begin to time the interval between the flash and the crash to learn how close they were to the actual spark . It can be concluded from the passage that _ . A) we should not believe what we see or hear. B) things moving downward are more noticeable. C) people sometimes may have wrong ideas about ordinary phenomena. D) adults are not as good as children in observing certain natural phenomena.
C
Invisible ink has fascinated kids for generations. You might think that it would be difficult to make, but it's not. All you'll need for this experient is some milk; some white paper; a clean cotton swab or small, clean paintbrush; the kitchen stove; and help from an adult. The most difficult part of this mini-project is choosing the message that you'll write with your invisible ink. Maybe you'll want to pretend that you're a spy on a secret mission, writing messages that would lead to big, big trouble if they were discovered. Choose your words carefully. All you need to do is, using the brush of cotton swab, write your message with milk on the paper. Don't use a lot of milk and soak the paper. Use just enough to make a thin coating. Once you've finished writing, ask the adult who's helping you to turn on the kitchen stove to a low heat. Very carefully, using kitchen mitts ,hold the paper about a foot above the warm burner. If you don't see results, you may have to make the burner a little hotter. Do not, however, hold the paper low over the burner. As the paper heats up, your message will become brown and you'll be able to see what was written. You want to know why? It's because chemical compounds in the milk have a low burning point. When the paper gets warm, those compounds will heat up and trun brown, while the paper will be unaffected. You also can try this experiment with other liquids, such as orange juice, lemon juice, vinegar, and apple juice. Just be sure to follow all safety rules and have an adult around to help you. What is probably the best title for the passage? A) A Scientific Research B) Making Invisible Ink C) How to Make a Spy D) A Classroom Experiment
B
Q: Tired of telling students to ask questions and to think about what they were doing, Damien Hynes, a high school geography teacher in Australia, decided to do an experiment to test what he had long been thinking.He wrote some well-organized nonsense (something untrue) on the blackboard.The students simply copied it but very few asked any questions.This shows that students are willing to believe anything given by teachers.The story is repeated in support of the Project for Enhancing Effective Learning (PEEL). PEEL was carried out by some teachers and researchers in Melbourne who had concluded that normal teaching methods seldom achieve their intended goals; what the teachers think they are teaching is one thing and what the students actually learn is something else.Students' lack of an over-all view of learning goals and their concentration on test scores make them see each lesson as a separate activity. Researchers realized that many students do not come into class empty-headed but have their own explanations of how the world works.Their own ideas can remain important to them even when they differ from scientific explanations that are learned later.In fact such ideas are hardly affected by traditional teaching.Students accept the teacher's scientific explanation, but do not drop their own.They simply keep both and use them practically: in a class test, they copy the teacher's idea, but in real life they use their own. Clearly what was needed was to make students understand their learning process , and this is what the PEEL teachers set out to deal with.On the surface, a class being taught by PEEL methods only differs from an ordinary class in being a little noisier, because more people are talking.But there are some meaningful changes.Students are given much more time to express their views, and teachers don't make immediate judgment.The students are allowed to guide what is done in class and their own ideas are always respected.This draws their attention to the actual learning process, and they become... Why did some teachers and researchers carry out PEEL? A) To ensure teachers do scientific work. B) To help students get higher test scores. C) To find the differences between what is taught and learnt. D) To help normal teaching methods achieve their goals.
A: D
We can see how the product life cycle works by looking at the introduction of instant coffee. When it was introduced, most people did not like it as well as "regular" coffee, and it took several years to gain general acceptance(introduction stage).At one point, though, instant coffee grew rapidly in popularity, and many brands were introduced(stage of rapid growth). After a while, people became attached to one brand and sales leveled off(stage of maturity). Sales went into a slight decrease when freeze-dried coffees were introduced(stage of decline). The importance of the product life cycle to marketers is this: Different stages in the product life cycle call for different strategies. The goal is to extend product life so that sales and profits do not drop. One strategy is called market modification. It means that marketing managers look for new users and market sections. Did you know, for example, that the backpacks that so many students carry today were originally designed for the soldiers? Market modification also means searching for increased usage among present customers or going for a different market, such as senior citizens. A marketer may re-position the product to appeal to new market sections. Another product extension strategy is called product modification. It involves changing product quality, features, or style to attract new users or more usage from present users. American auto manufacturers are using quality improvement as one way to regain world markets. Note, also, how auto manufacturers once changed styles eagerly from year to year to keep demand from falling. In order to attract more consumers, U.S. auto makers are _ . A) modernizing product style B) increasing product features C) developing products of better quality D) re-positioning their product in the market
C