16.authority

用法：复数authorities才表示当局，官方---the authorities concerned有关当局

an authority on---在...方面的权威---He is an authority on English. Authority over---对...人的凌驾---Chinese parents have more authority over their children.

17.base主要做具体的基础，basis主要做抽象的基础，其复数是bases

18.have a bearing on=have connection with与...有关

用法： Attention should be centred on the links that have a bearing on the situation as a whole. 应该注意那些涉及全局的重要关节

19.make an attack on…攻击

用法： and Joshua and all Israel with him went on to make an attack on Debir; 约书亚和以色列众人回到底璧，攻打这城.

20.avoid/escape doing; be void/devoid of common sense缺乏常识;

用法：void既是名词也是形容词一是是空的，无效的;devoid是一个形容词意思是空无的，缺乏的只能做表语