这里是北京阿龙视频:文章加评论

Sahara's Sands
How much of the Sahara Desert is covered by sand?
Mention the Sahara Desert and many people think of sand dunes stretching from horizon to horizon. While enormous fields of sand cover some parts of the Sahara, that sand only covers about 20% of the world's largest desert. The rest consists of rocky plateaus, open plains of gravel, and barren rocks.

From space, the Sahara is a mottled patchwork of browns and yellows. The bright yellow-white sand fields are especially prominent in the eastern and western regions, while the wrinkled, brown Ahaggar and Tibesti mountain ranges dominate the central area.

In the west, the great El Djouf basin ("The Belly") holds one of the largest expanses of sand in the world. This almost completely lifeless "empty quarter" of Mauritania is more than 1000 kilometers (600 miles) across. In the east there is even more sand, mostly concentrated in windblown trails running southwest across Egypt and Libya.

你查询一下然后登陆一些论坛网站，里面应该有你想要的内容，具体的网址，呵呵……我也不是很清楚，看看大家有没有说几个。

不要只会复制粘贴，还是真的本事最重要，找一篇简单的文章来读，不明白可以多读两遍，然后自己体会之后开始写评论。可能开始的时候比较困难，但是什么事情都是万事开头难，熬过去了，一切也就很顺畅了。战胜自己的惰性是最重要的。

My Family
I am Alice.I am ten years old.I live near the school.I go to school every day.In my family, there are three peole.My father ,my mother and I.My father is a boss. He is very busy.He has lot of friends.My mother is a salesman.She works at home.She does housework every day.I love them.