例句：Life in the middle of marriage if often compared to wire walking, for in the early years spouses attract each other and in late years they need each other.

15.In our life, there often appears such an occasion when…/on which…

例句：In our daily life, there often appears such an occasion when we drink success to our work in one field but, at the same time, begin to do great damage to other fields.

16.One of the great men one said that…/There is an old saying that…

例句：A gifted American psychologist once said that it is an illusion to believe in the Sunday-school truth—more comfort, more happiness.

17.According to the recent survey/statistics, there is…percent of…

例句：According to a recent survey made in a certain university, there are 43.8 percent of male students and 38.3 percent of female students either facing problems with nutrition or having to miss classes because of illness each term.

18.Nowadays, a heated debate/discussion about…is under way in China. Some people believe that…, whereas others argue that…