题目

声音在空气中的传播速度v(m/s)与温度T(℃)的关系如下表： 温度T/℃ 0 5 10 15 20 速度v/(m/s) 331 334 337 340 343 （1） 写出速度v与温度T之间的关系式； （2） 当T＝30℃时，求声音的传播速度； （3） 当声音的传播速度为346m/s时，温度是多少？ 答案：解：由图表可知，温度每升高1℃，音速就加快 35 m/s，v= 35T ＋331=331＋0.6T. 解：当T＝30℃时，v= 35×30 ＋331=349(m/s) 解：当v=346m/s时，346= 35T ＋331；解得T=25℃Forest guards in western India are using cell phones with ring tones of cows mooing, goats bleating and roosters crowing to attract leopards that have wandered into human settlements, officials said on Monday.The wild cats in the state of Gujarat often get into villages near forests in search of food, say officials, adding that this results in attacks on people. But rather than use methods such as live bait(诱惑物) like goats tied to trees to lure the leopards, which then fall into large pits dug by guards, officials say they have found a safer method to trap the cats.“The moos of a cow, bleating of a goat from the phone has proved effective to trap leopards,” said D. Vasani, a senior forest official in Gujarat. “This trick works.” Vasani said forest guards have downloaded the sounds of over a dozen animals as ring tones on their mobiles which they attach to speakers and fix behind a cage. They then play the ring tone continuously for up to two hours until the curious leopard appears and moves into the cage looking for its easy meal.At least five leopards have so far been lured from villages since the new ring tone method was introduced three months ago. The cats have all been released back into forest areas.Wildlife activists welcomed the new initiative saying that previous methods of trapping the cats using pits often resulted in the animals getting injured. 56. What can be the best title of the passage?A. Cell Phones to Hunt Animals B. Practical Uses of Cell PhonesC. Wildlife and New TechnologyD. Phone ring tones to Catch Leopards57. Forest guards in India try to catch leopards mainly because ______. A. leopards attack villagers B. they want leopard fur C. leopards attack animalsD. they have new ring tones58. According to the wildlife activists, the new method is _______.A. appreciated because it benefits leopards B. not good because it may injure animalsC. effective because ring tones workD. not safer than the former one59. We can learn from the passage except that ______.A. forest guards don’t mean to hurt the leopards B. forest guards no longer use pits to trap leopardsC. forest guards used goats to attract leopards D. recorded animal sounds are used to lure leopards60. What will be needed to trap the leopards using the new method?① cell phones    ②animals     ③ sounds of animals    ④ cages     ⑤large pits A. ①②③④       B. ②③⑤             C. ①④⑤            D. ①③④