题目

如图，点A、B的坐标分别为（0，2），（1，0），直线y=﹣3与坐标轴交于C、D两点．（1）求直线AB：y=kx+b与CD交点E的坐标；（2）直接写出不等式kx+b＞﹣3的解集；（3）求四边形OBEC的面积； 答案：【答案】（1）（2，﹣2）；（2）x＜2；（3）.【解析】（1）利用待定系数法求出直线AB的解析式，利用二元一次方程组求出点E的坐标；（2）根据函数图象写出不等式kx+b>x-3的解集；（3）根据坐标轴上点的特征求出C、D两点的坐标，根据三角形的面积公式计算即可.解：（1）由题意得，解得，故直线AB的  In a surprising discovery about where higher life can survive, scientists have found a shrimp —— like creature and a jellyfish swimming beneath an Antarctic ice sheet. About 180 meters below the ice where no light can get through, scientists had thought nothing much more than a few microbes (微生物) could exist. That’s why a NASA team was surprised when they lowered a video camera to get the first long look at the underbelly of an ice sheet in Antarctica. A curious shrimp – like creature came swimming by and then parked itself on the camera’s cable. Scientists also pulled up a tentacle (触须) they believe came from a jellyfish. “We were operating on the presumption that nothing’s there.” Said NASA ice scientist Robert Bindschadler. “It was a shrimp you’d enjoy having on your plate.” “We were just gaga (狂热的) over it,” he said of the 7.5cm long, orange creature starring in their two – minute video. Technically, it’s not a shrimp. It’s a Lyssianasid amphipod, which is distantly related to the shrimp. The video is likely to inspire experts to rethink what they know about life in harsh environments. And it has scientists thinking that if shrimp – like creatures can live below 180 meters of Antarctic ice in freezing dark water, what about other cold places? What about Europa, a frozen moon of Jupiter? Cynan Ellis – Evans, a scientist of the British Antarctic Survey called the finding fascinating. He said it was possible the creatures swam in from far away and don’t live there permanently. But Kim, who is a co-author of the study, doubts it. “The site in West Antarctica is at least 19 km from open seas. Bindschadler drilled a 20 cm – wide hole and was looking at a tiny amount of water. That means it’s unlikely that two creatures swam from great distances and were captured randomly in that small of an area,” she said. Yet scientist were puzzled at what the food source would be for these creatures. While some microbes can make their own food out of chemicals in the ocean, complex life like the shrimp can’t, Kim said. “So how do they survive? That’s the key question.” Kim Sai. “It’s pretty amazing when you find a huge puzzle like that on a planet where we thought we know everything.” Kim said. 1.What does the underlined word “harsh” probably mean? A. cold           B. loud          C. cruel           D. ugly 2.According to Kim, the shrimp – like creature        . A. swam great distances to Antarctic                     B. has always lived in the region C. gradually evolved from shrimps                         D. has nothing in common with shrimps 3.The finding is significant in that           . A. it marks NASA’S first Antarctic biological study B. it proves there is marine life in the Antarctic C. it could inspire further study of life in harsh environments D. it shows that Lyssianasid amphipod is closely related to shrimps 4.Which of the following statements about the discovery is FALSE? A. Complex life usually lives on other forms of life. B. Scientists saw two creatures in the two – minute video. C. It is possible for creatures to live 180 meters below the ice though there is no light. D. Scientists captured the shrimp – like creature in a camera by drilling a hole through the ice.