Types of Wars
Civil wars are fought between citizens of the same country and are fought within the country.
If citizens of a country disagree about a policy or leader, they may fight a civil war.
译文：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。如果一个国家的公民对政策或领导人意见不一，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.
A world war involves many or most of the world's most powerful countries.
There were two world wars in the 20th century.
译文：当国家结成联盟时，世界大战就开始了，而这些联盟又互相打仗。世界大战涉及世界上许多或大多数最强的国家。20世纪有两次世界大战。
Terrorism involves groups of individuals rather than countries.
Terrorists may come from different countries and they may share the same beliefs.
Terrorists often use car bombings ['bɑmɪŋs] and suicide attacks on innocent (['ɪnəsnt] 无辜的；无罪的) people.
A terrorist attack can happen at any time and any place.
译文：恐怖主义涉及的是个人团体，而不是国家。恐怖分子可能来自不同的国家，他们可能有一样的信仰。恐怖分子经常用汽车炸弹和自杀式袭击无辜人群。恐怖袭击随时随地都可能发生。
An invasion occurs when one country attacks another.
It sends its army into the other country and attempts to take control.
One of the most famous invasions was when France invaded Russia in 1812.
译文：当一个国家攻击另一个国家时，侵略就发生了。它派遣军队进入另一个国家，并妄图控制。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.
Most countries have a military so that it can defend itself if it's attacked.
When France invaded Russia in 1812, the Russian army fought a defensive war and defeated the French army.
译文：当一个国家受到攻击需要自卫时，就会发生防御性战争。大多数国家都有军队，这样一旦受到攻击，军队就可以自卫。1812年法国入侵俄国时，俄国军队打了一场防御战，最终打败了法国军队。
Exercise:
1.— What happens when citizens of a country fight each other?
— Civil wars are fought between citizens of the same country and are fought within the country.
2.— What is it when one country sends its army into another country?
— An invasion occurs when one country attacks another.
3.— What of war did Russia fight when it was invaded by France?
— When France invaded Russia in 1812, the Russian army fought a defensive war and defeated the French army.
4.— What of war involves many countries?
— A world war involves many or most of the world's most powerful countries.
5.— What involves groups of individuals rather than countries?
— Terrorism involves groups of individuals rather than countries.
6. If citizens of a country disagree about a policy or leader, they may fight a civil war.
7. Terrorism involves groups of individuals rather than countries.
8. A defensive war occurs when a country is attacked and needs to defend itself.
Repeat & Read Sentences:
1. If citizens of a country disagree about a policy or leader, they may fight a civil war.
2. Terrorism involves groups of individuals rather than countries.
3. An invasion occurs when one country attacks another.
4. Civil wars are fought between citizens of the same country and are fought within the country.
5. Terrorists may come from different countries and they may share the same beliefs.
Biology Terms
A cell is the basic unit of life.
A cell is the smallest structure that can live and reproduce.
Cells grow and develop, reproduce and interact with the environment.
译文：细胞是生命的基本单位。细胞是能够生存和繁殖的最小的结构。细胞生长、发育、繁殖并与环境相互作用。
Photosynthesis [,foto'sɪnθəsɪs] is one of the most important biological [,baɪə'lɑdʒɪkl] processes.
It allows plants to capture and use light as an energy source.
Photosynthesis is the process of converting light energy into chemical energy.
译文：光合作用是最重要的生物过程之一。它允许植物捕捉和利用光作为能源。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.
Once inside a cell, a virus reproduces and makes many copies of itself.
Some diseases such as influenza are viruses.
译文：病毒是攻击并进入细胞的小型生物结构。一旦进入细胞，病毒就会自我繁殖并复制很多自身的副本。有些疾病如流感是病毒。
Bacteria are one-celled forms of life that are all around us.
Although they have a single-cell structure, they are very important.
Many bacteria are inside us and help us digest our food.
译文：细菌是生活在我们周围的单细胞生物。虽然它们是单细胞结构，但它们非常重要。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.
Nearly every cell in a person's body has the same DNA.
The information stored in DNA tells cells what to do and is necessary [ˈnɛsəˌsɛri] for reproduction.
译文：DNA是一种复杂的分子，它储存信息并能自我复制。人体内几乎每个细胞都有相同的DNA。储存在DNA中的信息告诉细胞该做什么，这是繁殖所必需的。
Exercise:
1.— What biological structure attacks and enters cells?
— A virus is a small biological structure that attacks and enters cells.
2.— What complex molecule stores information about who and what we are?
— DNA is a complex molecule that stores information and can make copies of itself.
3.— What is the basic unit of life?
— A cell is the basic unit of life.
4.— What process allows plants to use light as an energy source?
— Photosynthesis allows plants to capture and use light as an energy source.
5.— What are one-celled forms of life?
— Bacteria are one-celled forms of life that are all around us.
6. A cell is the smallest structure that can live and reproduce.
7. A virus is a small biological structure that attacks and enters cells.
8. Many bacteria are inside us and help us digest our food.
Repeat & Read Sentences:
1. A cell is the basic unit of life.
2. Some diseases such as influenza are viruses.
3. Many bacteria are inside us and help us digest our food.
4. A cell is the smallest structure that can live and reproduce.
5. Although they have a single-cell structure, they are very important.
