171. on the corner, in the corner, at the corner

　　on the corner物体表面的角上;例：on the corner of the table

　　in the corner物体内部的角落里;

　　at the corner物体外部的角落上(拐角处)

　　172. warn sb. of, warn sb. against

　　warn sb. of提醒某人注意某事;

　　warn sb. against提醒某人不要做某事 例：warm him against swimming in that part of the river

　　173. at peace, in peace

　　at peace平静地;

　　in peace和平地 例：live in peace with one's neighbors

　　174. on earth, on the earth, in the earth

　　on earth在世上，在人间，到底，究竟，一点也不;

　　on the earth在地上，在地球上;

　　in the earth在地下，在泥土里

　　175. in surprise, to one's surprise, by surprise

　　in surprise惊奇地;

　　to one's surprise使某人吃惊的是;

　　by surprise使…惊慌 例：The question took the professor by surprise.