2016高考英语二轮阅读理解一百六十集选练（124）

　　2016高考模拟题。阅读理解阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。millions of years. But volcanic rock samples taken from the canyon now suggest that the canyon was down-cut instead.

　　Down-cutting is when a flood of water rushes over a landscape (地形) with enough force to cut deeply into the ground and leaves behind a canyon. Such a flood is usually released when a natural or man-made dam (堤坝) bursts.

　　Robert Webb, a research geologist, says natural dams seem to have formed and broken across the Colorado River several times during the last million years. The dams were built when lava(熔岩) from the eruptions of nearby volcanoes flowed into the river. The lava hardened into hard rocks and blocked the river, causing it to back up and form a lake. Each time the lake grew so huge that it broke the rock dam, releasing a flash flood that furthered the down-cutting process and deepened the canyon.

　　Down-cutting is not just an earthly event. Satellite photos sent back from Mars suggest that the process has happened there, too, say many other researchers.

　　The photos, taken by the Mars Global Surveyor, indicate that an enormous lake existed on Mars 3.5 billion years ago. The lake spilled into a large nearby hole. One edge of the hole broke, releasing a flash flood that quickly carved out a grand canyon.

【2016届高考英语二轮复习阅读理解一百四十集选练：（124）】相关文章：

★ 四川省2016届高考英语一轮复习课时作业（40） Module 4 Music Born in America 外研版选修8

★ 四川省2016届高考英语一轮复习课时作业（42） Module 6 The World’s Cultural Heritage 外研版选修8

★ 重庆市2014高考英语阅读理解一轮（精品）训练题（19）附答案

★ 2017高考四川省广安市英语阅读理解一轮系列训练：11（含解析）

★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练：第10组（含解析）

★ 2017届高考英语二轮复习书面表达限时测验：3（含解析）

★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练：第20组（含解析）

★ 【北京专用】2014届高考英语一轮复习方案课时作业：选修8 Unit 4 Pygmalion

★ 2017届高考英语二轮复习课时训练：17（含解析）

★ 贵州省贵阳市2014高考英语（新人教版）一轮阅读训练（22）附答案