2014
高考英语阅读理解抓分练习精品（22）及答案阅读理解----------------e the vienna-based researchers showed that dogs will stop doing a simple task when not rewarded if another dog, which continues to be rewarded, is present． the experiment consisted of taking pairs of dogs and getting them to present a paw for a reward．on giving this “handshake” the dogs received a piece of food．one of the dogs was then asked to shake
