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

　　on the corner物体表面的角上，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）on the corner of the table

172. warn¹ sb. of, warn sb. against²

　　warn sb. of提醒某人注意某事，warn sb. against提醒某人不要做某事

warn him against swimming in that part³ of the river

173. at peace⁴, in peace　　at peace平静地，in peace和平地 live in peace with one's neighbors⁵

174. on earth⁶, 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 no use on earth

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

The question took⁷ the professor⁸ by surprise.

176. in the air, on the air, in the sky

　　in the air正在酝酿中，on the air播送，广播，in the sky在天空中

His show is on the air at 6:00 tonight.

177. in the field⁹, on the field

　　in the field在野外，on the field在战场上 He lost his life¹⁰ on the field.

178. in the market¹¹, on the market

　　in the market表示场所或地点，在市场上，on the market出售

He sells fish in the market. Fresh¹² vegetables are on the market now.

179. in the sun, under the sun

　　in the sun在阳光下，under the sun地球上，全世界 people under the sun

180. in a voice¹³, with one voice

　　in a voice出声地，with one voice异口同声地 They refused with one voice.