s At 2 PM on December 5, 1945, five Navy aircraft took off in perfect flying weather from a naval air installation in southeastern Florida, on a routine training mission over the Atlantic Ocean. (Line 1, para1) ◆ routine 1) n accord with established procedure.例行公事的 eg. a routine check of passports检查护照的惯例 2) Habitual; regular.习惯性的;常规的 eg. made his routine trip to the store.照常去商店 3) Haying no special quality; ordinary平凡的;没有特征 的;普通的; eg. a routine day.平淡的一天1 . At 2 PM on December 5, 1945, five Navy aircraft took off in perfect flying weather from a naval air installation in southeastern Florida, on a routine training mission over the Atlantic Ocean. (Line 1, para1) w routine: 1) In accord with established procedure. 例行公事的 e.g. a routine check of passports 检查护照的惯例 2) Habitual; regular. 习惯性的；常规的 e.g. made his routine trip to the store. 照常去商店 3) Having no special quality; ordinary 平凡的；没有特征 的；普通的； e.g. a routine day.平淡的一天