40Cr中Cr的主要作用是（）。A、提高耐蚀性 B、提高回火稳定性及固溶强化F C、提高 发布时间：2018-09-01 05:30 │ 来源：www.tikuol.com 题型：单项选择题 问题： 40Cr中Cr的主要作用是（）。A、提高耐蚀性B、提高回火稳定性及固溶强化FC、提高切削性D、提高淬透性及固溶强化F
题型：单项选择题 阅读理解。 The population of the Earth is growing faster. It is important that we look after the Earth. We need it! The Earth gives us a lot of things. We also give the Earth a lot, but some of the things are not good. In nature, when something dies, other animals and plants get food from it. Every animal or plant gives food for other animals or plants. However, animals can't get food from many of the things that we "give"he Earth. Animals and plants can't eat metal, plastic and glass. These things will stay in the ground formany, many years. Some rubbish is very dangerous for plants and animals. In some places, many animals live together. One animal makes food for many more animals. If we put rubbish and chemicals in the water, the plankton(浮游生物) can die. If there isn't any plankton, many animals have nothing to eat. So what can we do? Don't leave any rubbish in the countryside! Don't make so much rubbish! 1. The Earth gives us ______. [ ]A. food B. rubbish C. chemicals D. pollution 2. When something dies in nature, ______. [ ]A. water and grass are polluted B. plastic and wood become food C. other animals and plants get food D. metal and glass stay in the ground 3. We must ______ to look after the Earth. [ ]A. put metal in the ground B. use more wood C. keep frogs in the water D. make less rubbish 查看答案
题型：单项选择题 患儿8岁，男，发热2天，咳嗽1天，伴咽痛流浊涕，头痛，易出汗，咳痰黄。查体：体温37.8℃，咽充血，舌质红，舌苔薄黄，脉浮数。此病例应诊为（）A.痰热咳嗽B.痰湿咳嗽C.阴虚燥咳D.风寒咳嗽E.风热咳嗽 查看答案
题型：单项选择题 文艺复兴时期，提倡“ * * ”否定“神权”的社会根源在于（ ）A．资本主义商品经济的发展B．反对天主教会，弘扬神性的封建思想C．资产阶级个人主义D．资产阶级反对封建束缚，要求自身的政治经济地位 查看答案