黑龙江省大庆市第十中学2019-2020学年高一10月月考英语试题

英语试题 第I卷 第一节 阅读理解 A There are two kinds of changes—chemical change and physical change. In a chemical change, there is always a new substance（物质）） formed. Breaking up water into hydrogen and oxygen is a chemical change. In each of the chemical change at least one new substance is formed. A change is not a chemical change if it doesn’t form a new substance. Physical changes are very common, too. There are many examples. You can make a physical change by tearing a piece of paper into two, or by cutting a piece of iron with lathe(车床). Here paper is still paper, and the iron is still iron. Another way of making physical change is dissolving(溶解) something in water. When you dissolve salt in water, the salt disappears. You may think that a new substance has been formed. But really there is no new substance. The salt is still salt. You can still taste it. So the dissolving of anything is a physical change. When water freezes, the change is also a physical one. The water changes from liq