地球的力量

In some cases, they can only be seen with the latest mapping techniques,like this one in Brazil.
有时候需要专家的绘图技术 才能揭示一个陨石坑的存在比如这个位于巴西的
But even with this technology,less than 200 impact craters have been found across the entire planet.
但即使是用最精密的设备 在整个地球上 找到的陨石坑也不超过200个

This is partly because erosion continually rubs out the evidence of past impacts,
部分原因是因为腐蚀现象 不断抹去过去冲击的证据
but it's also because of the atmosphere's protective role.
但是也是因为大气层发挥了保护作用
To understand how something as intangible as thin air protects us from meteors,
为了理解像空气这样薄稀的事物 如何保护我们不受陨石侵害
you need to find a meteorite that has survived its fall to Earth.
你需要寻找一个成功掉到地球上来的陨石
Meteorites are rare, so you need to go to great lengths to track one down.
陨石很稀少所以你需要费很大的劲去寻找
Dr Phil Bland is a planetary scientist on just such a mission,
菲尔·布兰德就是一个执行该使命的科学家
leading an expedition out onto the barren NuHarbor Plain
我跟他一起踏上了征程
in Western Australia, three days' drive from the nearest town.
到澳大利亚西部有三天的车程

重点讲解

1、continual
不停的;不间断的
The school has been in continual use since 1883.
自1883年以来，该校从未停办过。
They felt continual pressure to perform well.
他们不断感受到压力，促使他们好好表演。
一再的;反复的;频繁的
the government's continual demands for cash to finance its chronic deficit.
政府为补贴长期的财政赤字而对资金的持续需求
She suffered continual police harassment.
她不断受到警方的骚扰。
2、protective
保护的；防护的
Protective gloves reduce the absorption of chemicals through the skin.
防护手套可以减少皮肤对化学物质的吸收。
Protective measures are necessary if the city's monuments are to be preserved.
要保存城市古迹必须采取一些维护性措施。
呵护的；有保护欲的
He is very protective towards his mother.
他对他的母亲呵护备至。
Glynis was beside her, putting a protective arm around her shoulders.
格莉妮丝在她身边，呵护地用胳膊搂住她的肩膀。
3、protect
保护；防护
So, what can women do to protect themselves from heart disease?
那么，女性怎样做才能使自己不得心脏病呢？
A long thin wool coat and a purple headscarf protected her against the wind.
一件薄薄的羊毛长外套和一条紫色的头巾为她挡了风。
（保险单）为…提供保险
Many manufacturers have policies to protect themselves against blackmailers.
许多厂家都购买了保险，以防遭到敲诈。