on prep.在...之上；由...支撑着；在（某一天）；关于；基于adv.穿着；向前（移动)；表示持续性adj.表示已连接、处于工作状态或使用中；发生；值班
详细释义
Adverb:
for examination (with an option to buy);
"they took the VCR on approval"
双语例句
Goods sent on approval must be paid for at the time of ordering, but if goods are returned within7 days customers will get their money back in full. 商店送出供试用的货物在订购时必须付款，但顾客如在七天之内退货，就可将原款全部收回。
Mr Grey bought his camera on approval. 格雷先生买这架照相机，包退包换。
