托福听力在线学习资料_托福听力
北京爱思学托福听力在线学习:朗读下列和地理地质有关的句子,改善对于geology的篇章熟悉度。考生们一起来备考吧。
朗读下列和地理地质有关的句子,改善对于geology的篇章熟悉度。【TPO5听力文本(Conversation+Lecture)】
听力(5)Lecture geology class.
1)The "Empty Quarter" is a huge area of sand that covers about a quarter of the Arabian Peninsula.
2)But they've been times in the past when monsoon rains soaked the Empty Quarter and turned it from a desert into grassland that was dotted with lakes and home to various animals.
3)Keep in mind though that this study only looked at 19 formations. And about a thousand have been documented.
4)So, the theory is, the lakes formed there, along the desert floor, in these long narrow valleys.
5)Another difference,very important today for distinguishing between older lake beds and newer ones,is the location of the limestone formations. The more recent beds are high up in the dunes.
6)So, during the second rainy period, the dunes were kind of chopped up at the top,full of hollows and ridges, and these hollows would've captured the rain right there on the top.
7) So they survive on much less. Interestingly,there are clams and snail shells; but, no fossils of fish. We're not sure why.Maybe there is a problem with the water. Maybe it was too salty. That's certainly true of other desert lakes.