听力原文
昨天的石菊化石，是小编我Daisy的成果。今天，我可发现了新的大陆，那就是攀岩，这可是新开发的野外极限运动啊，你准备好了吗？Go! Go! Go!

When the ammonites became extinct, the map of North America looked completely different: to the north, the Canadian Rocky Mountains already existed; to the south, the American Rockies had yet to rise. The date of the ammonites' extinction holds a key to when they first emerged.

These animals died about seventy million years ago in the middle of the Western Interior Seaway. And so we know at that time about seventy million years ago that this site was below sea level. So we know then that the Rocky Mountains had to rise from that seaway sometime after seventy million years ago.

Today all that is left from the ancient seafloor are these fossilized remains high in the Colorado Rockies.

Next, geologists needed to find out what pushed the seafloor up. The investigation moves to these slabs of rock flanking the Rockies just outside Denver, Colorado. They are known as the Flatirons, and they are part of the same formation that make up the Red Rocks' amphitheater. These slabs of rock are unusual because they contain holes, holes that make the Flatirons appealing to climbers and geologists alike.

So when we go climbing in the Flatirons, we are climbing on really nice handholds, in some cases, handholds that have been formed either by the pebbles in the rock or by zones of fine grained material that are easily removed by erosion the shales and the siltstones. Those layers get removed, leaving a notch for the hands to go in, and it makes for fantastic climbing.

The holes are a clue as to how these strangely tilted Flatirons were formed.

The layers themselves, the different grain sizes in the layers the silt, the sand, the pebbles this tells us that these are sedimentary rocks.

Sediments form in water when sand and small pieces of rock settle on the ground. Over millions of years they get compressed into layers of rock.

小编有约：呵呵~~看看我给大家准备的礼物。A. Denver, Colorado B. Rock C. holes
这里的线索能让你想起什么东西来？
听力答案
答案就是 "Flatirons "。在地质学中，它是(熨斗状的三角形陡峻的)平顶脊，也叫熨斗形山，在现实生活中，它是熨斗，铬铁的意思。你猜到了吗？

参考译文
石菊灭绝后，北美的这块土地看上去已经完全不同：在北边，加拿大的落基山脉开始形成，而南边，美国这部分的落基山脉尚未形成。石菊消亡之日就是落基山脉开始形成的关键日。

大约在七千万年前，这些动物在西部内陆海道中相继死去。因此，我们知道在大约七千万年前，这个地方是在海平面以下。然后，我们知道落基山脉在75万年前的某个时间，从这个海道中慢慢升起。

今天，这片古老的海床留给我们的化石却在科罗拉多州落基山高高的山峰中。

接下来，地质学家需要探索究竟是什么原因使海床向上。通过调查，我们来到与落基山侧面相接的岩石群，这里位于科罗拉多州丹佛市。他们被称为平顶脊(熨斗状的三角形陡峻的岩石群)，这片岩石群是红岩石露天剧场的一部分。岩石群不同寻常的地方在于岩石中的孔，洞。这些洞孔吸引着大批的登山者和地质学家来到这里。

所以，我们可以借助这些天然的扶手去攀登这片平顶脊。一般情况下，岩石中的卵石或者成片成片的被侵蚀了的页岩和沙泥岩共同构成这些天然的扶手。当岩石的表面一层一层地剥落后，留下一条一条的凹槽，就变得非常适宜人攀登。

这洞孔也告诉我们这奇形怪状的平顶脊是如何形成的。

同时岩石层本身也告诉我们，它们通过海底的沉淀而来，因为在岩石上面沉积有不同大小的颗粒如粉砂，砂石，卵石。

现在看到的沉积物是由海里的砂石以及小岩石组成的。经过数百万年的演变，他们已经压缩成今天的岩石层。

小编的译文，仅供参考。如果有更好的译文，请给小编一些建议，Daisy在这里将非常感激大家。在后面一页的重点讲解，也是小编原创，所以转载的同仁，请注明转载来源，谢谢啦！

重点讲解
注释：① extinct adj. 灭绝的，绝种的；熄灭的 vt. 使熄灭
例句：
1. If we continue to destroy the countryside many more animals will become extinct.
我们若继续破坏自然环境，将会有更多的动物绝种。
2. Dinosaurs have been extinct for millions of years.
恐龙已绝种几百万年了

② emerge vi. 浮现；摆脱；暴露
例句：
1. Cultural differences also emerge in employee attitudes.
员工的态度也存在文化差异。
2. My sheep and cattle will emerge before your eyes.
风吹草低见牛羊。

③ remains n. 残余；遗骸
例句：
1. The remains of the supper were taken away.
晚餐吃剩的东西被收去了。
2. In the high valleys, there are remains of glaciers, while below them are clear, icy lakes which the glaciers made.
高山山谷里有着冰川的遗迹。在冰川的下游，有一些冰川形成的清澈而冰冷的湖泊。

句子讲解：

1.When the ammonites became extinct, the map of North America looked completely different: to the north, the Canadian Rocky Mountains already existed; to the south, the American Rockies had yet to rise.

　　【结构简析】这句话中使用了冒号，它分别说明了南边是一个什么样的情况，北边又是什么样的情况，句子的意思很简单。Daisy建议像这样的句式我们可以在写作文的时候，尝试着去这样写，可以给老师非常地道的英文思维。

　　【参考译文】石菊灭绝后，北美的这块土地看上去已经完全不同：在北边，加拿大的落基山脉开始形成，而南边，美国这部分的落基山脉尚未形成 。

　　2. So when we go climbing in the Flatirons, we are climbing on really nice handholds, in some cases, handholds that have been formed either by the pebbles in the rock or by zones of fine grained material that are easily removed by erosion the shales and the siltstones.

　　【结构简析】这句话可不短，我们就抓主谓宾，那就是"we are climbing "。这就是核心句子，其他的部分是说明"handholds"的，以及它的构成情况是怎样的。

　　【参考译文】所以，我们可以借助这些天然的扶手去攀登这片平顶脊。一般情况下，岩石中的卵石或者成片成片的被侵蚀了的页岩和沙泥岩共同构成这些天然的扶手。