Hummingbirds have got their name from the distinct "hum" sound made by their rapidlyflapping  wings. The size of the bird decides the number of flaps it can do. The average lifetime of a hummingbird is 3 or 4 years, but some of them have lived beyond 12 years also. They are unique in many ways. Besides the number of rapid flaps they can do per second, they can also fly backwards. Hummingbirds have an amazing sense of assessing the amount of sugar in thenectar  they eat. They feed on the nectar of flowers. Hummingbirds do not feed on flowers whose nectar contains less than 10% sugar. Talk about a sweet tooth! As they cannot sustain themselves on nectar alone because of its poor nutritional value, they also feed on insects and spiders, and hummingbird food mixture that one can make at home. Attracting hummingbirds to your garden will require a little planning. Plant butterfly bush, mimosa, coral bells, foxglove, morning glory, etc. These flowers attract the hummingbirds due to their highvisibility  and nectar production. Avoid usingpesticides , as it will not only kill the insects around the flowers, but hurt the hummingbirds as well. A common food for these birds is the sweettastingsugar syrup . Hummingbird food ingredients are just two: sugar and water. Take a large clean bowl, pour in it four cups of hot water, and dissolve one cup of table sugar in it. Stir slowly until all sugar has dissolved. Hummingbirds, tiny as they are, collect a lot of nutrition. Providing them with hummingbird food mixture made of sugar water is a sure way to get all these beauties humming in your garden. In order to attract hummingbirds, you should  _  . A) plan high trees B) grow plants with small flowers C) grow plants whose flowers are bright in color D) grow plants coming into flower in the morning
C
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Albert Einstein died long ago. However, a group of researchers have created a robot which looks like the great scientist.  The robotic Einstein is very special because the researchers at the University of California, San Diego (UCSD) have taught their realistic robot to smile, frown and make other complex facial expressions. Scientists believe that babies learn to control their bodies through movements, including learning to speak. "We use the same idea to work out the problem of how a robot could learn to make realistic facial expressions," said Javier Movellan, director of UCSD's machine Feeling Lab. ks5u The San Diego researchers directed the Einstein robot's head to turn in all directions. The robot could see its expressions in a mirror and then use the software to provide data for machine-learning to match facial expressions to the movements of its small motors. Once the robot learned the relationship between facial expressions and the muscle movements, it learned to make facial expressions. Its head has about 30 facial feelings, and each is moved by a tiny motor connected to ht e skin by s sting. Although we've never met Albert Einstein, we have a feeling that the new robot isn't exactly a fair representation of now of the best minds of the 20th century. The figure does not have the grace of the great man, but it can recognize human expressions and react to them in the right way. In fact, if you smile at it, it will smile right back to you. "As far as we know, no other research group has used a robot to make realistic facial expressions," said computer scientist Tingfan Wu, a computer science PhD student who worked on a more exact facial expression robot. How does the robotic Einstein make the muscle movements?. A) Some software directs tiny motors to do it. B) It begins to do that after learning how to smile. C) The researchers move its muscles up and down. D) It learns to do that only with a mirror.
A
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There is no question that teenagers need rules, which is often not a difficult thing for parents to give. What can be more challenging is giving teenagers their freedom. It can be difficult to draw the line between the two. However, some issues cannot be changed by discussion and require firm rules. For instance, rules should be established concerning driving the family car. I will admit that I have no problem coming up with rules. To me they make life easier and they leave no room for questioning. What can be more difficult, however, is giving my teens their freedom. I guess there are really two primary reasons for this. One is that I sometimes am afraid to give them freedom. The second is that I'm not always so sure what the freedom should be. It helps that I have a husband with whom I can discuss these problems. We talk about _ , give our thoughts and then we come up with an agreement. Sometimes one of us might be more unwilling but we know that there comes a time when we really do have to learn how to let go of the reins   a bit. If we try to make life have nothing but rules, we are more likely to see our teen's rebelling  . They need to know that while we do have certain expectations, we also trust them to begin making their own choices and decisions. How else can they do that unless they are given the space and room to do it? It's really all about balance and I will be the first to admit that it can be a challenge to carry out. However, it is a necessary part of growing up. Yes, teens definitely need rules but they also need freedom. According to the text, we can infer that the writer  _  . A) refuses to give her children freedom B) finds it difficult to make rules C) doesn't have a good relationship with her children D) has trouble in giving freedom to her children
D
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Over thirty thousand years ago,people from northern Asia   went to America.Today, we call these people Indians . The Indians went to America because the weather began to change.Northern Asia became very cold. Everything froze. They had to move or die. How did the first Indians go to America? They walked! Later Columbus found the New World in 1492.At first,only a few Europeans followed .They travelled to America in boats. For the next three hundred years, about 500,000 people went there. Then the number grew very quickly. From 1815 to 1915,over thirty-two million Europeans left their countries and went to the United States. The biggest groups were from Germany and Italy .These Europeans spoke many different languages.Most of them took almost no money.They went to America so that they could find a better life. _   went to America first. A) People from northern Asia B) People from Europe C) People from Germany D) Columbus

A
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