17.I bought a dress for only 10 dollars in a sale;It was a real ____.
A.exchange B.bargain C.trade D.business.
18.Always read the _____ on the bottle carefully and take the right amount of medicine.
A.explanations B.instructions C.descriptions D.introductions
17.答案是B,bargain名词，便宜货，廉价货,a real bargain 真便宜。
18.答案是B,explanation解释；instructions 指示，说明；descriptions 描述；introduction 介绍。
