eg：The computer enables people to communicate with each other more conveniently.计算机使人们彼此间能更方便地交流。

　　2、be about to do sth… when 正要做某事……突然……

　　eg：I was about to go shopping when it suddenly began to rain.我刚要出去买东西，天就突然下雨了。

　　3、by accident/by chance/accidentally 偶然地

　　4、come across sb 偶然遇见

　　5、act on sth 依……行事

　　eg：Each student should act on the rules and regulations of the school.每个学生都应该遵守学校的规章制度。

　　6、add to/add up to 加上/总计达

　　eg：The number of the patients added up to three hundred last week.上星期，病人人数达到了三百人。

　　7、in advance/ahead of time 提前

　　8、after all 毕竟

　　9、agree to do sth/agree with sb 同意做某事/同意某人