2. 专升本
  3. Not until the twentieth century did engineers fully understand the principles of flight that birds have been using for millions

Not until the twentieth century did engineers fully understand the principles of flight that birds have been using for millions

admin2015-02-09  84
问题 Not until the twentieth century did engineers fully understand the principles of flight that birds have been using for millions of years.
选项
答案直到20世纪，工程师们才完全弄懂鸟儿千百万年来一直应用着的飞行原理。
解析
转载请注明原文地址:https://kaotiyun.com/show/w8UC777K
本试题收录于： 英语题库普高专升本分类
0

英语

普高专升本

相关试题推荐
随机试题
最新回复(0)