175. doubtful of /about怀疑
176. drop by / in 顺路拜访
177. due to 由于,因为
178. each other 互相
179. easier said than done说起来容易做起来难180. east of在...东面
181. equal to相等,胜任
182. equivalent to等于,相当于
183. essential to/for必不可少
184. even if/though 即使,虽然
185. ever so 非常,极其
186. every now and then 时而,偶尔
187. every other 每隔一个的
188. except for 除了...外
189. expert at/in/on善于
190. face to face 面对面地
191. faculty members 教职员工
192. faithful to忠实于
193. fall flat 平躺在地上
194. familiar to sb为...所熟悉
195. familiar with sth熟悉,通晓
196. far from 远非,远离