Types of Wars类型的战争
Civil wars are fought between citizens of the same country, and are fought within the country.内战发生在同一个国家的公民之间，也发生在这个国家内部。
If citizens of a country disagree about the policy or leader, they may fight a civil war.如果一个国家的公民对政策或领导人有不同意见，他们可能会打一场内战。
A world war is fought when countries form alliances, and these alliances fight each other.当国家结成联盟，而这些联盟又互相争斗时，世界大战就爆发了。
A world war involves many or most of the world's most powerful countries.世界大战涉及世界上许多或大多数最强大的国家。
There were 2 world wars in the 20th century.20世纪有两次世界大战。
Terrorism involves groups of individuals rather than countries.恐怖主义涉及个人团体胜过国家。
Terrorists may come from different countries, and they may share the same beliefs.恐怖分子可能来自不同的国家，他们可能共享相同的信仰。
Terrorists often use car bombings and suicide attacks on innocent people.恐怖分子经常用汽车炸弹和自杀式袭击无辜的人。
A terrorist attack can happen at anytime and anyplace.恐怖袭击随时随地都可能发生。
An invasion occurs when one country attacks another.当一个国家攻击另一个国家时，侵略就发生了。
It sends its army into the other country, and attempts to take control.它派遣军队到另一个国家并试图控制。
One of the most famous invasions was when France invaded Russia in 1812.最著名的入侵之一是1812年法国入侵俄罗斯。
A defensive war occurs when a country is attacked and needs to defend itself.当一个国家受到攻击需要自卫时，就会发生防御性战争。
Most countries have a military, so that it can defend itself if it's attacked.大多数国家都有军队，所以一旦受到攻击，军队可以自卫。
When France invaded Russia in 1812 the Russian army fought a defensive war and defeated the French army.1812年法国入侵俄国时，俄国军队打了一场防御战，打败了法国军队。
Throughout history there have been many invasions.历史上有许多侵略。
Biology Terms生物学方面
A cell is the basic unit of life.细胞是生命的基本单位。
The cellis the smallest structure that can live and reproduce.细胞是能够生存和繁殖的最小的结构。
Cells grow and develop, reproduce and interact with the environment.细胞生长、发育、繁殖并与环境相互作用。
Photosynthesis is one of the most important biological processes.光合作用是最重要的生物过程之一。
It allows plants to capture and use light as an energy source.它允许植物捕捉和利用光作为能源。
Photosynthesis is the process of converting light energy into chemical energy.光合作用是把光能转化为化学能的过程。
A virus is a small biological structure that attacks and enters cells.病毒是一种攻击并进入细胞的小型生物结构。
Once inside a cell, a virus reproduces and makes many copies of itself.一旦进入细胞，病毒就会自我复制并复制很多次。
Some diseases such as influenza are viruses.有些疾病如流感是病毒。
Bacteria are one-celled forms of life that are all around us.细菌是生活在我们周围的单细胞生物。
Although they have a single-cell structure, they are very important.虽然它们是单细胞结构，但它们非常重要。
Many bacteria are inside us and help us digest our food.许多细菌在我们体内帮助我们消化食物。
DNA is a complex molecule that stores information and can make copies of itself.DNA是一种复杂的分子，它可以储存信息并复制自己。
Nearly every cell in a person's body has the same DNA.几乎每个人体内的细胞都有相同的DNA。
The information stored in DNA tells cells what to do, and is necessary for reproduction.储存在DNA中的信息告诉细胞该做什么，这是繁殖所必需的。
Many bacteria are inside us and help us digest our food.许多细菌在我们体内帮助我们消化食物。
cells are often called the building blocks of life 细胞通常被称为生命的基石
there are billions of bacteria in our intestines我们的肠道里有数十亿的细菌
some bacteria are very dangerous and can caouse disease有些细菌非常危险，会引起疾病
