、阅读理解（本大题共5小题，共0分）

　　A

　　Studying carbon atoms (碳原子) locked up in tooth enamel (珐琅质), two researchers argue against the widely held belief that hominids ate little more than fruits and leaves. Sponheimer and Julia Lee-Thorp of the University of Cape Town, South Africa, report their findings in Friday's Science.

　　There aren't many,clues for us to know the life of early hominids. The shape of hominids' teeth offered the first clues. Large and flatedged with thick enamel, they looked perfect for eating nuts and fruits, different from the sharp teeth one would want to tear into meat with. The first stone tools, which would help in eating meat, didn't appear until about half a million years later.

　　Scientists have also found marks on hominids' teeth with patterns very similar to those on the teeth of modernday fruit eaters. Sponheimer and Lee-Thorp tried a new method, looking at the chemical composition of the tooth enamel. They studied the enamel for the carbon-13. Animals that eat grasses have higher carbon-13 levels than those eating fruits and other plants.

　　What they found was that the teeth of the hominids had an in-between amount of carbon-13, which meant not only they were eating fruits, they were eating a lot of grasses, or animals eating grasses. The lower carbon-13 levels could also come from eating certain types of insects (昆虫).

【2017高考英语三轮冲刺阅读强化训练37】相关文章：

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (39)

★ 四川省广安市2014高考英语一轮基础训练题（9）及答案

★ 2017高考四川省广安市英语阅读理解一轮系列训练：16（含解析）

★ 湖南省岳阳市2014高考英语一轮单项选择训练题（5）及答案

★ 河南省三门峡市2014高考英语一轮（暑假）基础训练（2）附答案

★ 2017届高考英语三轮冲刺复习：完形与阅读强化训练37

★ 河南省三门峡市2014高考英语一轮（暑假）基础训练（3）附答案

★ 2017届高考英语二轮复习大题冲关秘籍语法填空：体验真题（含解析）

★ 2017届高考英语二轮复习大题冲关秘籍语法填空：考纲解读（含解析）

★ 2017高考四川省广安市英语阅读理解一轮系列训练：18（含解析）