第4讲+选词填空专题+导学案 上海市暑期初升高一衔接英语.docxVIP

PAGE 23 教学内容 Section B Directions: Complete the following passage by using the words in the box. Each word can only be used once. A. A. resulting B. repeatedly C. relatively D. unusual E. difficult F. fluent G. fed H. mastered I. planning J. previously K. convenient How and why, roughly 2 million years ago, early human ancestors evolved large brains and began making (31) advanced stone tools, is one of the great mysteries of evolution. Some researchers argue these changes were brought about by the invention of cooking. They point out that our bite weakened around the same time as our larger brains evolved, and that it takes less energy to absorb nutrients from cooked food. As a result, once they had (32) the art, early chefs could invest less in their digestive systems and thus invest the (33) energy savings in building larger brains capable of complex thought. There is, however, a problem with the cooking theory. Most archaeologists (考古学家）believe the evidence of controlled fire stretches back no more than 790, 000 years. Roger Summons of the Massachusetts Institute of Technology has a solution. Together with his team, he analyzed 1.7-million-year-old sandstones that formed in an ancient river at Olduvai Gorge in Tanzania. The region is famous for the large number of human fossils that have been discovered there, alongside an impressive assembly of stone tools. The sandstones themselves have (34) yielded some of the worlds earliest complex hand axes-large tear-drop-shaped stone tools that are associated with Homo erectus (直立人) . Creating an axe by (35) _________ knocking thin pieces off a raw stone in order to create two sharp cutting edges requires a significant amount of (36) , Their appearance is therefore thought to mark an important moment in intellectual evolution. Trapped inside the Olduvai sandstones, the researchers found (37) biological molecules (分子）that a