They were surprised that a four-year-old boy should work out such a difficult problem ____ they themselves couldn’t.
183. Hearing the funny speech given by the famous professor, all of us burst into _____.
182. To the sea captain’s surprise, he found thattravel could also be quite pleasant.
181. In the hospital, there are a lot of _____.
180. There is a _____ of understanding between them. Otherwise, they will be good friends.
179. In China, the majority of men earn their living by manual ______.