163. implicit a. 内含的;含蓄的> If it is ~, it is implied.
164. impulse n. 冲动
165. incidence a. 发生率
166. indignant a. 愤怒的
167. infectious a. 传染的
168. ingenious a. (人)灵巧的; (设计等)巧妙的 ~ handicraftsman
169. inherent a. 固有的 the ~ defects of planned-economy
170. initiate v. 开始;发起 ~ a new plan
171. integral a. 构成整体所必须的;不可缺的 Rice is an ~ part of Chinese diet.
172. intelligible a. 明白易懂的
173. intensify v. 加剧 The noise intensified.
174. intermittent a. 断断续续 the ~ rain showers
175. intimidate v. 恐吓 176. intricate a. 错综复杂的
177. intrinsic a. 固有的 ~ value
178. intuition n. 直觉 Your ~ is your sixth sense.