Steps in the Scientific Method | Examples |
State the problem or question. | "Why doesn"t the water level in a glass rise when ice melts?" |
Collect information about the problem, using your own observations and research. | You already know that ice is frozen water. From your research, you learn that water and ice are made of water molecules (分子). |
Form a hypothesis, or a best guess based on the information. | "The molecules in water appear to be closer together than they are in ice." |
Test the hypothesis by doing an experiment. | Fill four glasses with ice. Then pour water over the ice and fill each glass to the rim. As the ice melts, you observe that the water does not spill over the top of the glasses. Each time you repeat the experiment, you get the same results. |
Draw a conclusion based on your results. | Molecules are closer together in water than they are in ice. |
阅读理解。 | |
Dogs wag (摇摆) their tails in different directions depending on whether they are excited and wanting to move forward or threatened and thinking of moving back, a study has found. Researchers in Italy examined the tail wagging behavior of 30 dogs, catching their responses to a range of stimuli (刺激物) with video cameras. To conduct the study they chose 15 male dogs and 15 female ones aged between one and six years. The dogs were all family pets whose owners had allowed them to take part in the experiment at Bari University. The dogs were placed in a large wooden box with an opening at the front to allow for them to view various stimuli. They were tested one at a time. The researchers led by Professor Giorgio Vallortigara of the University of Trieste found that when the dogs were shown their owners-a positive experience-their tails wagged energetically to the right side. When they were shown an unfamiliar human they wagged to the right, but with somewhat less enthusiasm. The appears of a cat again caused a right-hand side wag, although with less intensity again. The appearance of a large unfamiliar dog, similar to a German shepherd, changed the direction of tail wagging to the left. Research ers supposed the dog was thinking of moving back. When the dogs were not shown any stimuli they tended to wag their tails to the left, suggesting they preferred company. While the changes in the tail wagging were not easily noticed without the aid of video, it was thought that the findings could help people judge the mood (心情) of dogs. Computer and video systems, for example, could be used by professional dog trainers to determine the mood of dogs that they were required to approach. | |
1. The video cameras were used to catch the dogs"responses because _____. | |
A. it was easier to catch the dogs"response changes in the tail wagging B. the dogs were put in the wooden boxes and tested one at a time. C. they enabled the dogs"owners to know about their dogs"habit D. the dogs wagged their tails in different directions when they were in different moods | |
2. The underlined word "intensity" in the passage means _____. | |
A. surprise B. worry C. excitement D. interest | |
3. When there are no stimuli, a dog will _____. | |
A. wag to the left B. wag to the right C. not wag at all D. wag to the left and then to the right | |
4. The underlined word "they" refers to _____. | |
A. the dogs B. the trainers C. the systems D. the researchers | |
5. The purpose of doing the experiment is _____. | |
A. to train dogs for their owners B. to help people judge the mood of dogs C. to help dogs find company D. to help people choose their pet dogs | |
阅读理解。 | |
Worrying about how you"ll perform on a math test may actually contribute to a lower test score, US researchers said on Saturday. Math anxiety-feelings of dread and fear and avoiding math-can weaken the brain"s limited amount of working capacity, a resource needed to calculate difficult math problems, said Mark Ashcrafi, a psychologist at the University of Nevada Las Vegas who studies the problem. "It turns out that math anxiety occupies a person"s working memory," said Ashcraft, who spoke at the annual meeting of the American Association for the Advancement of Science in San Francisco. Ashcraft said while easy math tasks such as addition require only a small part of a person"s working memory, harder calculations require much more. Worrying about math takes up a large part of a person"s working memory stores as well, spelling disaster for the anxious student who is taking a high-stakes test ( 高风险测验). Stress about how one does on tests like college entrance exams can make even good math students choke. "All of a sudden they start looking for the short cuts," said University of Chicago researcher Sian Beilock. Although test preparation classes can help students get over this anxiety, they are limited to students whose families can afford them. Finally, she said, "It may not be wise to rely completely on scores to predict who will succeed." While the causes of math anxiety are unknown, Ashcraft said,"People who manage to get over math anxiety have completely normal math ability." | |
1. Sian Beilock points out that stress________. | |
A. can"t be avoided before college entrance exams B. contributes to scores in college entrance exams C. has no effects on good math students D. has side effects on students in college entrance exams | |
2. What does the underlined word "spelling" probably mean? | |
A. causing B. reducing C. taking away D. preparing for | |
3. What can we learn from the text? | |
A. The causes of math anxiety have already been found. B. All of the students attend test preparation classes. C. Math anxiety weakens working memory needed to do math. D. Few measures can be taken to get rid of math anxiety. | |
4. What does the passage suggest middle school students do before exams? | |
A. Get relieved. | |
阅读理解。 | |
By Zhang Youlv (China Daily 09/29/2008)-A manned lunar (月球的) landing is China"s next target when the current three-stage space program ends in the next dacade."When our manned space program is completed, we will travel even further," Wang Zhaoyao, deputy head of China"s manned space program office and Shenzhou VII mission spokesman, told a briefing in Beijing three hours after China"s third manned space mission was successfully concluded yesterday. "After comprehensively analyzing the general trend of the international development of manned space, as well as realities in China, we see a manned lunar landing as a both challenging and tactical (策略的) field in global hi-tech," he said. "We believe it necessary for our country to do something in this field," Wang said. He did not give a specific(具体的) date for a moon landing. Wang, however, said,"Experts believe this is "very much needed" for research into relevant (closely connected) technologies to further China"s achievements in space." The 68-hour Shenzhou VII mission featured a 25-minute spacewalk on Saturday. It was broadcast live and watched by millions throughout the country. The crew"s landing at a site in the Inner Mongolia autonomous region was also carried live by national television. The entire mission was pronounced a complete success. Wang said the three astronauts, were transported to Hohhot, the region"s capital, and would spend the evening there. "They will return to Beijing this morning," he said. "During the course of the mission, Russian experts provided strong technical support for the EVA spacesuits. The successful Sino-Russian cooperation for this flight created beneficial conditions for more intensive cooperation between the two sides in the future," Wang said. The mission"s success has paved the way for completing the second stage of the program-building a space station before 2020. Before that, a space lab will be set up in 2010 with Shenzhou X, the country"s next full-crew space journey. | |
1. When will China"s spaceship land on the moon? | |
A. 2020. B. 2010. C. 2018. D. No specific date. | |
2. What does the underlined sentence in the fourth paragraph imply? | |
A. We will travel even further in the outer space. B. There is a need for China to land on the moon. C. It is very much needed to research space technologies to further China"s space program. D. International cooperation is necessary for China"s landing on the moon. | |
3. The reason why Russian experts provided strong technical support for the EVA spacesuits is that _____. | |
A. China can"t make spacesuit B. China and Russia would like to cooperate in space program C. China is a leading technological power now D. Russia wants to benefit from China | |
4. What would be the best title for this passage? | |
A. A Manned Lunar Landing is Both Challenging and Tactical B. Shenzhou X will Land on the Moon C. China will Set up a Space Lab on the Moon D. Landing on the Moon--the Next Target |