AChemicalChangeandPhysicalChange.Therearetwokindsofchanges--chemicalchangeandphysicalchange.Inachemicalchange,thereisanewsubstance（物质）formed.Breakingup（分解）waterintohydrogen（氢气）andoxygenisachemical

Question

A Chemical Change and Physical Change.There are
two kinds of changes--chemical change and physical change.
In a chemical change,there is a new substance（物质）formed.Breaking up （分解）water into hydrogen （氢气）and oxygen is a chemical change.In each of the chemical changes,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 pape in two,or by cutting a piece of iron with a 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 fomed .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 a liquid to a solid.But it is still the same substance.That is why the freezing of anything is a physical change.
1．In writing the passage,the writer mainly tells us .
A．how matters are formed
B．the kinds of matters
C．what is chemical change and what is physical change
D．why substances change
2．In a chemical change,.
A．a new substance is formed
B．at least more than one new substance is formed
C．there isn’t any new substance formed
D．both A and B
3．A change is not a chemical ch

Answer 1

化学变化和物理变化
自然界有两种类型的变化,化学变化和物理变化.　　
在化学变化中,有一个新的物质形成的.水分解为氢气和氧气是化学变化.在每一个化学变化,至少一个形成新的物质.如果没有形成新的物质,那么这个改变就不是一个化学变化.
物理变化是很常见的.这方面有很多例子.你可以把一张指撕成两片或从铁床上削减一块铁.纸仍然是纸,铁仍是铁.　　
物理变化的另一种方法是溶解的东西在水里.当你在水中溶解盐,盐就会消失.你可能认为一个新的物质已经成立了.但是真的没有新的物质,盐还是盐,你还可以品尝它.所以任何的溶解就是一个物理变化.
当水结冰时,也是一种物理现象.水从液体变为固体,但它仍然是相同的物质.这就是为什么上冻是一个物理变化.　　　　
1 C 2.A
纯手工翻译 望采纳 谢谢