12月英语六级完形填空练习及答案

树瑶风分享2013-03-05 03:38:45 次阅读

2017年12月英语六级完形填空练习及答案

　　英语是现在世界上用的最多的`一门语言，许多国家都在学英语和用英语，所以，学好了英语，出门就不怕沟通不方便了。下面是小编为大家搜索整理的英语六级辅导训练，希望能给大家带来帮助!

　　Leonardo da Vinci was the first man to suggest that growing trees add a new ring in their trunks each year. The 11 in these rings relates to the physical conditions which the tree experiences. Thus, trees grown in a 12 area and time each develop a pattern or configuration of their rings.

　　This 13 was of little significance until Andrew E. Douglas began to study tree rings in Arizona in 1900. Using a technique called cross dating, he was able to employ tree rings to the study of archae

ological sites and date the ruins with 14 . Some were as old as 6700 B. C. ! This study of tree rings is called dendrochronology.

　　In time the cross dating was 15 by a carbon 14 process. This approach measured the amount of carbon 14 radiating from a piece of wood and 16 to determine the age of that wood. Further use of the carbon 14 technique has shown that the radiation process is more complex and less 17 than had been at first thought.

　　The most 18 aspect of tree ring research is now called

　　dendroclimatology. This 19 of the reconstruction of climates and climatic cycles and events from the evidence found in the tree rings. From this it is hoped that a 20 of drought cycles can be determined in the American Southwest. Such information will be of great help in determining the life and ecology of that region of the United States.

　　A. thus

　　B. model

　　C. variation

　　D. concept

　　E. accuracy

　　F. exciting

　　G. consists

　　H. given

　　I. proposition

　　J. composes

　　K. further

　　L. pattern