In parts of the Caribbean, the manatee, an endangered marine mammal, has long been hunted for its meat. Having noted the manatee hunters' expert knowledge of manatees' habits, local conservationists are encouraging the hunters to stop hunting and instead to take tourists on boat rides to see manatees. Tourist interest is high, so the plan has promise of achieving the twin goals of giving the former hunters a good income and helping ensure the manatees' survival.
Which of the following, if true, raises the most serious doubt about the plan's chance of success?
AA 一个公司要省新员工培训费,决定让老员工参加一个program,记录他们的habits and activities,让新员工follow,以省去高昂的cost AI 说fossil fuels很宝贵,应该adopt international 条规来减少各国对fossil fuels 的dependence
MATH 1 K大于M,问K的值。K,M都是正整数(狗里有) a. K^2+M^2=25 b. K^3+M^3=91
2 员工有经济学学位的80%和会说法语的40% 每个员工either有学位or会所法语or both 求既会说法语有有学位的人(狗里有) 确实是求‘the precent of people who have XXX also can speak Frence’ 50% 3 地图填色问题,AB(C)D,A与B与D相邻,C在B里,不挨着A与D,题意好像是说有三种颜色可用,共几种方案(狗里有) 有个图 最后36
4 Which line in the following is perpendicular(垂直) to line y = 5x(狗里有,补充选项) Answer include: y = -5x , y= (1/5)x, y = (-1/5)x , y=1/(5x) , y=-1/(5x) 就选y = (-1/5)x 5 已知a,b为正,5a-7(b+3)=2,问a-b最不可能是下面哪项(之前的狗主人记错数字了) A. 1B. 2 C. 4 D. 5 E.7 算来算去A B都不行,犹豫半天选了A ----新狗 6 一个桌布,搭在桌子上四周都垂下来1/2 inch,桌子长x宽y,求8个桌布垂下来的面积 8x+8y-8 7 有五条射线,每两个间隔角度为20、15、25、30 求任取两个射线所得的0~180°角度有几种 我选的10 8 一个公司,有CPAs 60%,一共有40%男工人,80%的男工人都是CPAs,求有多少女CPAs 60%-40%*80%=28%(貌似。。) 9 DS 求n^2 mod 3=1 a n是偶数 b n^2=9k^2+6k+1 我选的B
GWD那个原题 In parts of the Caribbean, the manatee, an endangered marine mammal, has long been hunted for its meat. Having noted the manatee hunters’ expert knowledge of manatees’ habits, local conservationists are encouraging the hunters to stop hunting and instead to take tourists on boat rides to see manatees. Tourist interest is high, so the plan has promise of achieving the twin goals of giving the former hunters a good income and helping ensure the manatees’ survival. Which of the following, if true, raises the most serious doubt about the plan’s chance of success? 1.Many tourists who visit these parts of the Caribbean are uninterested in manatees and would not be willing to pay what the former manatee hunters would have to charge for boat rides to see manatees. 2.Recovery of the species would enable some hunting to continue without putting the manatees’ survival in jeopardy again. 3.In areas where manatees have traditionally been hunted for food, local people could easily replace the manatee meat in their diets with other foods obtained from the sea. 4.There would not be enough former manatee hunters to act as guides for all the tourists who want to see manatees. 5.To maintain their current income, manatee hunters who switched to guiding tourists would have to use far larger boats and make many more trips into the manatees’ fragile habitat than they currently do. 是选5吧~
谁帮我解释下 2 员工有经济学学位的80%和会说法语的40% 每个员工either有学位or会所法语or both 求既会说法语有有学位的人(狗里有) 确实是求‘the precent of people who have XXX also can speak Frence’ 50% 为什么是50%? 学位交法语不是20%,然后20%/80%不是25%吗?
谁帮我解释下 2 员工有经济学学位的80%和会说法语的40% 每个员工either有学位or会所法语or both 求既会说法语有有学位的人(狗里有) 确实是求‘the precent of people who have XXX also can speak Frence’ 50% 为什么是50%? 学位交法语不是20%,然后20%/80%不是25%吗?
About how dolphins distinguish their own sounds from the others in the ocean Paragraph 1: 海豚怎样辨别自己的声音让专家觉得很有意思之类。。。因为在海里有很多很多的杂音。还举了一个浅水地方的例子,说海底里有很多小虾子发出的clicks Paragraph 2: 海豚发出的click trains and whistles seem designed to distinguish their own sounds from the others’. 而且whistles 有很规律性的变法 (unvarying pattern)。实验里面证明了海豚会等到接受了第一个clicks 的echo之后才发出第二个click trains
Echolcation - the location of objects by their echos - is a highly specialized faculty that enables dolphins to explore their environment and search out their prey in a watery world where sight is often of little use. As sound travels four and a half times faster in water than in air, the dolphin's brain must be extremely well adapted in order to make a rapid analysis of the complicated information provided by the echoes.
Although the ability to echolcate has only been proven experimentally for a few odontocete species, the anatomical evidence - the presence of the melon, nasal sacs and specialized skull structures - suggests that all dolphins have this ability.
The dolphin is able to generate sound in the form of clicks, within its nasal sacs, situated behind the melon. The frequency of this click is higher than that of the sounds used for communication and differs between species. The melon acts as a lens which focuses the sound into a narrow beam that is projected in front of the animal. When the sound strikes an object, some of the energy of the soundwave is reflected back towards the dolphin. It would appear that the panbone in the dolphin's lower jaw receives the echo, and the fatty tissue behind it transmits the sound to the middle e ar and thence to the brain. It has recently been suggested that the teeth of the dolphin, and the mandibular nerve that runs through the jawbone may transmit additional information to the dolphin's brain. As soon as an echo is received, the dolphin generates another click. The time lapse between click and echo enables the dolphin to evaluate the distance between it and the object; the varying strength of the signal as it is received on the two sides of th e dolphin's head enable it to evaluate direction. By continuously emitting clicks and receiving echoes in this way, the dolphin can track objects and home in on them.
The echolocation system of the dolphin is extremely sensitive and complex. Using only its acoustic senses, a bottlenose dolphin can discriminate between practically identical objects which differ by ten per cent or less in volume or surface area. It can do this in a noisy environment, can whistle and echolocate at the same time, and echolocate on near and distant targets simultaneously - feats which leave human sonar experts gasping.