The tiny parts that all living things are made of.
细胞 —— 构成所有生物体的最小单位。
BookEvery part of our body is made up of tiny cells.p. 108
MorePut a drop of pond water under the microscope and you will see hundreds of cells moving.
单数是 cell /sel/。课文里的 white blood cells 是白细胞，red blood cells 是红细胞。
A tool that makes very small things look much bigger.
显微镜。
BookBeth uses a microscope to see plant cells.p. 108
MoreWe looked at salt under a microscope and saw tiny cubes.
micro-（小）+ -scope（看）＝看小东西的仪器。对比 telescope（tele- 远）望远镜。形容词 microscopic 极小的。课文里的 electron microscope 是电子显微镜。
A very tiny thing that gets inside the body and causes sickness.
病毒。
BookA virus can enter your body through your nose or mouth.p. 108
MoreA flu virus can spread from one person to another in a crowded room.
复数 viruses。形容词 viral（病毒的；网络上疯传的）。
Very tiny living things. Some kinds can make you sick, but many are helpful.
细菌（复数形式）。
BookSome bacteria can make people very sick.p. 108
MoreBacteria in your stomach help break down the food you eat.
单数是 bacterium。bacteria 本身就是复数，后面要跟复数动词：Bacteria are everywhere. 形容词 bacterial。
An illness that affects the body.
疾病。
BookEating healthy food can protect you from a disease.p. 108
MoreHeart disease is a serious health problem in many countries.
常见搭配：catch / have / spread a disease。构词 dis-（不）+ ease（舒适）＝不舒服。近义词 illness，但 illness 更强调「生病这个状态」。
A serious illness like a very bad cold; also called the flu.
流感。influenza 是正式/医学说法，日常口语说 the flu。
BookThomas was in bed for two days with influenza.p. 108
MoreEvery autumn, doctors tell old people to have an influenza vaccination.
不可数名词。口语用 flu，并且要带 the：have / catch the flu。
A mild illness with sneezing and a runny nose.
普通感冒。
BookMany students get sick with the common cold every year.p. 108
MoreThere is no cure for the common cold; you just have to rest and drink water.
固定带 the。区分：have a cold（得了一次感冒，可数）／the common cold（这种病本身）。课文里它还能作定语：the common cold virus（普通感冒病毒）。
The thick, wet substance inside the nose and throat.
黏液 —— 鼻腔和咽喉里黏稠的分泌物。
BookA body usually makes more mucus when it is sick.p. 108
MoreMucus traps dust and viruses before they can reach your lungs.
不可数名词，不加 -s。形容词 mucous。口语里「流鼻涕」说 a runny nose。
Unable to be harmed by a disease.
有免疫力的；不受……侵害的。
BookMaria can't get the flu because she is immune to it.p. 108
MoreOnce you have had a disease, your body may become immune to it.
固定搭配 be immune to sth —— 介词是 to，这是考点。名词 immunity 免疫力；课文里的 immune system 是免疫系统。
To make all or part of the body unable to move.
使瘫痪；使麻痹。
BookDr. Butler uses a wheelchair because his legs are paralyzed.p. 108
MoreThe accident paralyzed him from the waist down.
教材原句用的是过去分词 paralyzed 作形容词（be paralyzed）。名词 paralysis 瘫痪。英式拼写也写 paralyse。
To give a sickness to a person or living thing.
感染；传染（使……染病）。
BookA sneeze or cough can infect another person.p. 108
MoreThe virus can infect the cells deep inside your lungs.
搭配 infect sb with sth（使某人感染某病）。派生：infected 被感染的、infection 感染、infectious 传染性的。
A set of clothes worn for a special job or activity.
一套（专用）服装。
BookYour skin acts like a suit of armor.p. 108
MoreFirefighters wear a special suit that protects them from heat.
课文里的 a suit of armor 是一套盔甲。另一常用义是西装（a business suit），作动词时表示「适合」：That color suits you.
n. A small injury where the skin is rubbed off. · v. To rub the skin against something rough and hurt it.
擦伤（名词）；擦破、刮伤（动词）。
BookBut if you have a cut or scrape, viruses may get in.p. 108
MoreHe fell off his bike and scraped his knee.
课文里和 cut（割伤）并列，都是「皮肤破了的小伤」。近义词 scratch（抓痕）。a scraped knee 擦破的膝盖。
A liquid.
液体；流体。
BookSome of the viruses … get trapped in a slimy fluid called mucus.p. 108
MoreYour body loses fluid when you sweat, so drink water after sport.
可数、不可数都可以（体液说 body fluids）。近义词 liquid。它也能作形容词：fluid 流动的。
Past form of swallow: made food, drink, or air go down the throat.
吞下（swallow 的过去式和过去分词）。
BookMucus carries the viruses to the back of the throat, where they are swallowed.p. 108
MoreShe swallowed the pill with a glass of water.
原形 swallow /ˈswɒləʊ/。同一拼写还有名词「燕子」，靠上下文区分。课文里用被动：they are swallowed（它们被吞下去）。
take a closer look at sth
仔细看看（某物）
To look at something more carefully so that you can see the details.
BookI'll shrink down to their size to take a closer look.
MoreIf the picture is too small, take a closer look at it with a magnifying glass.
这里 close 读 /kləʊs/（近的），不是 /kləʊz/（关上）。
come in many different shapes
有各种不同的形状
To exist in many different forms, sizes, or shapes.
BookJust like bacteria, viruses come in many different shapes, like balls, bullets, and rods.
MorePasta comes in many different shapes — tubes, shells, bows, and ribbons.
come in + 颜色／尺寸／形状 是高频句型：The shirt comes in three sizes.
the immune system
免疫系统
The body's natural system that fights disease.
BookThank goodness the body has an immune system to fight viruses.
MoreSleep and healthy food help your immune system work well.
与 immune 同源，名词是 immunity（免疫力）。
defend oneself
自我保护；自我防御
To protect yourself from attack or harm.
BookLet's look at how our bodies defend themselves.
MoreSome animals defend themselves by changing color.
反身代词随主语变：defend myself / yourself / itself / themselves。名词 defense（美）/ defence（英）；课文里的 first defenses 是第一道防线。
act like
起……的作用；表现得像
To do the job of something else, or to behave the way something else does.
BookYour skin acts like a suit of armor.
MoreThe thick fur acts like a coat and keeps the animal warm.
对比 look like（看起来像，说的是外表）。act like 后面直接跟名词。
be made of
由……制成（看得出原料）
To be formed from a material that you can still see or recognize.
BookIts top layer is made of dead cells, so viruses can't find live cells to infect.
MoreThe old bridge is made of stone.
三兄弟要分清：be made of 看得出材料（桌子 made of wood）／be made from 材料已变样（纸 made from wood）／be made into 被做成（葡萄 made into wine）。
get in
进入（体内）；进来
To enter a place or the body.
BookBut if you have a cut or scrape, viruses may get in.
MoreWash the cut at once so that dirt cannot get in.
短语动词。进到某个具体地方用 get into sth。反义 get out。别和 get on（上公交/火车）搞混。
breathe in
吸入
To take air into your lungs.
BookWhen you breathe in viruses, some of them get trapped in your nose hairs.
MoreBreathe in slowly through your nose, then out through your mouth.
反义 breathe out（呼出）。名词 breath /breθ/（一次呼吸），动词 breathe /briːð/ 多一个 e、多一个音。
get trapped in
被困在……里
To be unable to get out of a place.
BookSome of the viruses … get trapped in a slimy fluid called mucus.
MoreThe fish got trapped in a small pool when the river dried up.
get + 过去分词 表示被动或状态变化：get trapped / get lost / get hurt / get infected。
make it past
成功越过（防线）
To get to the other side of something that is blocking you.
BookSome of the viruses that make it past the hairs get trapped in a slimy fluid called mucus.
MoreFew cars made it past the fallen tree on the road.
make it ＝成功做到。课文两种说法都有：make it past the hairs 和 get past these first defenses，意思一样。
be destroyed by
被……摧毁／杀死
To be completely damaged or killed by something.
BookWhen the viruses reach your stomach, they're usually destroyed by stomach acids.
MoreThe old houses were destroyed by the fire.
被动语态 be + destroyed + by。近义 be killed by。名词 destruction。
come to one's aid
前来帮助某人
To come and help someone.
BookWhen our cells are under attack, white blood cells come to their aid.
MoreWhen the boat started to sink, another ship came to their aid.
正式书面表达，也可以说 come to sb's help。同一句里的 be under attack 是「正受到攻击」。
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