Đổi các câu sau thành câu bị động 
171. Someone turn off the lights when I went out.
172. You must do your exercises more carefully.
173. Did they cut those flowers this morning ?
174. Student are doing lots of work.
175. People don't like her much.
176. Somebody has cleaned my shoes and washed my shirts.
177. People must not leave bucycles against the wall.
178. They show me the easier way to do it.
179. They used to start those cars by hand.
180. People said that Jack was a clever student.