地球的力量

As rivers flow over rocks and stones,they gradually wear them down.
随着河水流过岩石和石块 渐渐腐蚀了它们
This releases salts trapped inside the rocks
这就释放出了岩石中的盐分
which are carried down to the ocean as sediment.
然后被带到海洋成为沉积物

Once in the ocean, the salts slowly become more concentrated
一旦进入海洋，盐就会慢慢集中
by millions of years of evaporation.
经过几百万年的蒸发
But salt was not the only thing left behind by the vanishing Mediterranean.
但是当时消失的地中海 留下的并不只有盐
If you're prepared to really search,
如果你准备好了寻找一下
you can find leftovers that are far more exciting
会发现更激动人心的残留物
than plain old table salt.
比普通的食盐更好玩
In this cave, there's something so precious
在这个山洞里有件很宝贵的东西
that I am one of the few people who's ever been allowed to see it.
只有包括我在内的几个人看到过
This is a geode, and these are giant rock crystals,more than a metre long.
这是一个晶洞这些是巨大的白水晶 有一米多长
This is some of the largest crystals I've ever seen.
这是我见过的最大的水晶
重点讲解

1、concentrate
全神贯注;集中（心思）
It was up to him to concentrate on his studies and make something of himself.
是否能专心学习并取得一定成就要靠他自己。
Water companies should concentrate on reducing waste instead of building new reservoirs.
自来水公司应该集中精力减少水浪费，而不是修建新水库。
使集中;使汇集
Italy's industrial districts are concentrated in its north-central and north-eastern regions.
意大利的工业区集中在该国中北部和东北部地区。
Most development has been concentrated in and around cities.
土地开发主要集中在城市及周边地区。
2、vanish
消失;失踪;突然不见
He just vanished and was never seen again.
他就这么消失了，再也没人见到过他。
The aircraft vanished without trace.
飞机消失得无影无踪。
(物种）灭绝;（传统）消亡
Near the end of Devonian times, thirty percent of all animal life vanished.
在泥盆纪末期，30％的动物物种都灭绝了。
all the species of birds that had vanished from Iowa.
艾奥瓦州所有消失了的鸟类物种