【正确答案】 C

【答案解析】[听力原文]
   Current studies show that what goes on labels is an important consideration for manufacturers, since more than seventy percent of shoppers read food labels when considering whether to buy a product.
   A recent controversy as to whether labels on prepared foods should educate or merely inform the consumer is over, and a consumer group got its way. The group had maintained that product labels should do more than simply list how many grams of nutrients a food contains. Their contention was that labels should also list the percentage of a day's total nutrients that the product will supply to the consumer, because this information is essential in planning a healthy diet.
   A government agency disagreed strongly, favoring label that merely informs the consumer, in other words, a label that only lists the contents of the product. The agency maintained that consumers could decide for themselves if the food is nutritious and is meeting their daily needs.
   The consumer group, in supporting its case, had cited a survey in which shoppers were shown a food label, and were then asked if they would need more or less of a certain nutrient after eating a serving of this product. The shoppers were not able to answer the questions easily when they were not given a specific percentage.
   This study, and others helped get the new regulation passed, and now food products must have the more detailed labels.
   According to the speaker, how many percent of customers read food labels before making a purchase?
短文从一开头就提到，食品生产商很关注食品标签上的内容，因为有超过于70%的消费者购买食品前会读食品上的标签。
   本题为数字题。预读选项，听音时要留意文中出现的数字，再进行信息匹配。