【正文】 en time before two years of age, and only occasional educational DVDs after that. Researchers have found a connection between screen time and a host of behavioral and physical problems. Some children have bee so addicted to iPads and other tablet devices (平板電腦裝置 ) that their parents have even sought out treatment. So, should I be perturbed about the increasing dependence on technology in our schools? In addition to a weekly puter class, my firstgrade daughter spends much of her instructional school day in front of the “smart board”. And now, school districts across the country are talking about replacing textbooks with tablets. There are several factors that need careful consideration. Important distinctions must be drawn between television screen time (yes, even educational programming), which is a mostly passive medium, and tablet screen time, which is more interactive (互動的 ). Another important factor is the age of the child. All people need human interaction, but babies and small children need it most of all. Studies have suggested that tablets may help improve reading and writing abilities in schoolaged children, however, plus they help children with autism (a mental disorder) municate. Tablets in the classroom could replace expensive and heavy textbooks, allow children to make and read notes more easily, providing interactive functions and help track progress. When I was a child, I could hardly carry my backpack up my driveway — we could avoid a lot of back problems by using one light and thin tablet instead of huge textbooks. Beyond mon concerns (what happens if the tablet is lost, stolen or broken?), I do worry about that we are rushing toward a brave new world of technology without considering what we might lose. If our children spend too much time on tablets, they run the risk of being addicted and missing out on a lot of what the world has to offer, especially in a time when schools are cutting art, music and gym. Human brains need realworld connections, touchable sensations and even some downtime. Tablets can be a part of child’s education, but we have to guard against these devices taking over. 29. The underlined word “perturbed” in Paragraph 2 is closest in meaning to “_______”. A. curious B. happy C. excited D. worried 30. According to Paragraph 3, allowing very young children to use tablets _______. A. is worth a try B. may be harmful C. helps improve their learning skills D. offers them more human interactions 31. The author mentions her childhood experience to _______. A. express her support for traditional education B. stress the importance of taking notes C. show the disadvantages of textbooks D. describe her happy childhood 32. Which may be the author’s opinion on tablets? A. They’re helpful only in a limited way. B. They are too expensive for most students. C. They excite students’ interest in learning. D. They improve the effectiveness of education. D Which animal has the fastest snapping jaw (突然合住的顎 )? If you’re guessing a shark or perhaps a larger animal, you’ll have to think smaller. The trap jaw ant, which lives in Central and South America, moves its mouth parts at 35 to 63 meters per second. Another way to think about this is that the ant’s jaws close at 125 to 233 kilometers per hour. That’s 2,300 times faster than the blink of an eye. Scientists were able to measure the amazing jaw speed using highspeed video techniques. Sheila Patek, a biologist, says the key is that the jaws have a springy (有彈性的 ) system, which is critical in getting explosive (爆發(fā)性的 ) speeds. Consider a bow and arrow. If you try to throw an arrow with your arm, it won’t go very far. If you use a bow, elastic energy stored in the bow is freed almost immediately when you let go of the arrow with your finger. That’s exactly what really fast anisms are doing. Maybe even more amazing than how fast these ants grab food or even enemies is how they use this same energy to move. As the ant closes its jaws, it uses them to push off the ground — all faster than the eye can see without slow motion video. A snap of the jaw can send an ant up to centimeters into the air. That’s like someone who is meters jumping 13 meters high! Not only can they quickly escape from enemies, but often a group of ants will start jumping all at once. It would be hard for their enemies to grab just one. 33. The fast speed of the trapjaw ants’ jaws lies in ______. A. their light bodies B. their springy systems C. their living environment D. the length of their jaws 34. What does the passage use “a bow and arrow” as an example to show? A. How an arrow gets so much energy to fly. B. Why the trapjaw ants have a springy system. C. Why the trapjaw ants’ j aws move so fast. D. How a bow and arrow works. 35. According to the passage, the trapjaw ants’ jaws keep them safe because ______. A. they can catch their enemies easily with their jaws B. their jaws ma