2019年英语六级考试口语短文背诵3

学习是一点点进步的过程，俗话说逆水行舟，不进则退，学习亦是如此。大家报考英语六级考试口语部分，就应该坚持自己的选择，不断探索，吸取知识。当然坦途网英语六级考试频道小编也会陪着大家度过考前艰难的备考时间，相信大家一定会有收获的。

罕见化石记录

A Rare Fossil Record

The preservation of embryos and juveniles is a rate occurrence in the fossil record. The tiny, delicate skeletons are usually scattered by scavengers or destroyed by weathering before they can be fossilized. Ichthyosaurs had a higher chance of being preserved than did terrestrial creatures because, as marine animals, they tended to live in environments less subject to erosion. Still, their fossilization required a suite of factors: a slow rate of decay of soft tissues, little scavenging by other animals, a lack of swift currents and waves to jumble and carry away small bones, and fairly rapid burial. Given these factors, some areas have become a treasury of well-preserved ichthyosaur fossils.

The deposits at Holzmaden, Germany, present an interesting case for analysis. The ichthyosaur remains are found in black, bituminous marine shales deposited about 190 million years ago. Over the years, thousands of specimens of marine reptiles, fish and invertebrates have been recovered from these rocks. The quality of preservation is outstanding, but what is even more impressive is the number of ichthyosaur fossils containing preserved embryos. Ichthyosaurs with embryos have been reported from 6 different levels of the shale in a small area around Holzmaden, suggesting that a specific site was used by large numbers of ichthyosaurs repeatedly over time. The embryos are quite advanced in their physical development; their paddles, for example, are already well formed. One specimen is even preserved in the birth canal. In addition, the shale contains the remains of many newborns that are between 20 and 30 inches long.

Why are there so many pregnant females and young at Holzmaden when they are so rare elsewhere? The quality of preservation is almost unmatched and quarry operations have been carried out carefully with an awareness of the value of the fossils. But these factors do not account for the interesting question of how there came to be such a concentration of pregnant ichthyosaurs in a particular place very close to their time of giving birth.

本文整理的六级口语短文背诵应该对大家很有帮助，口语就是不断练习，不断纠正发音的过程，每天朗读或者背诵一篇英语短文，不仅对大家的语言表达能力有提升，而且对语感也会很有帮助。大家只要想着以通过英语六级考试为目标，就会每日坚持下来，晨读背诵，相信很快就会有成效的。