【正文】 reas once teeming with frogs and toads, it is being less and less easy to find those slimy, hopping and sometimes poisonous 中國最大的管理資源中心 (大量免費資源共享 ) 第 2 頁 共 7 頁 members of the animal kingdom. All over the world, and even in remote parts of Australia, frogs are losing the ecological battle for survival, and biologists are at a loss to explain their demise. Are amphibians simply oversensitive to changes in the ecosystem? Could it be that their rapid decline in numbers is signaling some ing environmental disaster for us all? This frightening scenario is in part the consequence of a dramatic increase over the last quarter century in the development of once natural areas of wet marshland。 home not only to frogs but to all manner of wildlife. However, as yet, there are no obvious reasons why certain frog species are disappearing from rainforests in Australia that have barely been touched by human hand. The mystery is unsettling to say the least, for it is known that amphibian species are extremely sensitive to environmental variations in temperature and moisture levels. The danger is that pla Earth might not only lose a vital link in the ecological food chain (frogs keep populations of otherwise pestilent insects at manageable levels), but we might be increasing our output of air pollutants to levels that may have already bee irreversible. Frogs could be inadvertently warning us of a catastrophe. An example of a species of frog that, at far as is known, has bee extinct, is the platypus frog. Like the wellknown Australian mammal it was named after, it exhibited some very strange behaviour。s mouth. Discovered in 1981, less than ten years later the frog had pletely vanished from the crystal clear waters of Booloumba Creek near Queensland39。 natural habitat is being more and more are being made to halt the development of wet are important in the ecosystem because they control platypus frog became extinct by usually give birth to their young in an underwater frog species have bee extinct so far in is convincing evidence that the ozone layer is being is a fact that frogs39。, in much the same way that owning a telephone links us to almost anyone who pays a phone bill. In fact, since the puter connections are made via the phone line, the Inter can be envisaged as a work of visual telephone links. It remains to seen in which direction the Information Superhighway is headed, but many believeit is the educational hope of the future. The World Wide Web, an enormous collection of Inter addresses or sites, all of which can be accessed for information, has been mainly responsible for the increase in interest in the Inter in the 1990s. Before the World Wide Web, the `Net39。 in 1990 allowed not only text links to be made but also graphs, images and even video. A Web site consists of a `home page39。(or screens) at the site and on thousands of other puters all over the world. This is achieved by a process called `hypertext39。 can go traveling, or surfing39。 can go traveling, or `surfing39。 promoting your club, your institution, your pany39。. Because of the relative freedom of access to information, the Inter has often been criticised by the media as a potentially hazardous tool in the hands of young puter users. This perception has proved to be largely false however, and the vast majority of users both young and old get connected with the Inter for the dual purposes for which it was intended discovery and delight. TRUE／ FALSE／ NOT GIVEN is aware of the Information the Inter costs the owner of a telephone extra puter connections are made by using telephone World Wide Web is a work of puterised to the author, the Information Superhighway may be the future hope of process called`hypertext39。is the first screen of a `Web39。. media has often criticised the Inter because it is . The latest technological revolution will change the way humans municate. Practice 3 The Australian political scene is dominated by two major parties that have