题目

(2019·山东师范大学附中高三第二次模拟考试)If you ask most people what water tastes like, they'll probably tell you that water has no taste and they may give you a funny look. But if you were a fruit fly, asking another fruit fly, that question might have a different answer. To a fruit fly, water has a taste. Scientists want to know how the fruit fly knows water because this information may help in learning how other animals—or even individual cells—manage to use water in the right way. Water is vital to life, but too much or too little can be deadly to a living creature. So by understanding how the fruit fly tastes water, researchers may learn more about other living things. According to the new study, a protein (蛋白质) called PPK28 makes it possible for a fly to taste water. Proteins build cells and tissues, fight disease and carry messages between cells. It's not surprising that a protein is responsible for the fruit fly's ability to taste water. The PPK28 protein is part of a larger family of similar proteins. One of these related proteins is used by mammals (including humans) to taste salt. Scientists have not found a protein that enables humans to “taste” water. In the experiment, Cameron and his team compared normal fruit flies with fruit flies whose taste cells had been disabled. The fruit flies were given a special chemical that would glow (发光) when the fly used the PPK28 protein. Then the scientists led the flies to water. When the normal flies tasted the water, the PPK28 protein lit up—showing that it was in use. The fruit fly in particular is so interesting that some scientists are hard at work creating a complete map of the fruit fly brain. This map will show all of a fly's neurons and help scientists understand how the neurons work together. 篇章导读：本文是一篇说明文，讲述了科学家研究果蝇可以分辨水有滋味的原因。获取这些信息有助于人类对其他生物甚至是单个细胞的研究和了解。 17．How do most people feel when asked the taste of water? A．Amused.                             B．Frightened. C．Disappointed.                       D．Disgusted. 18．Why do scientists want to know how the fruit fly knows water? A．To decrease the number of the fruit fly. B．To know more about other creatures. C．To manage to use water correctly. D．To describe the taste of water. 19．What do we know about the PPK28 protein? A．It can make humans taste salt. B．The fruit fly can't live without it. C．It enables the fruit fly to taste water. D．The fruit fly uses it to avoid illnesses. 20．What will the scientists continue to work at? A．Studying the fruit fly's neuron systems. B．Telling more information about cells. C．Creating maps of human brains. D．Making the PPK28 protein. 答案：17.A　细节理解题。根据第一段第一句“If you ask most people what water tastes like, they'll probably tell you that water has no taste and they may give you a funny look.”可知，当人们被问及水的滋味时，他们会感到这个问题很可笑，故选A。 18.B　推理判断题。根据第二段第二句“Scientists want to know how the fruit fly knows water because this information may help in learning how other animals—or even individual cells—manage to use water in the right way.”可知，科学家通过研究果蝇如何分辨水的滋味来更多地了解其他生物，故选B。 19.C　细节理解题。根据第三段第一句“According to the new study, a protein (蛋白质) called PPK28 makes it possible for a fly to taste water.”可知，PPK28蛋白质使得果蝇能够辨别水的滋味，故选C。 20.A　细节理解题。根据最后一段第一句中的“that some scientists are hard at work creating a complete map”和第二句“This map will show all of a fly's neurons and help scientists understand how the neurons work together.”可知，科学家们会继续致力于研究果蝇的神经元是如何协同工作的，故选A。

查看本题答案和解析