【2005年阅读Text 1 第3段】
In the world of capuchins, grapes are luxury goods (and much preferable to cucumbers). So when one m&111nkey was handed a grape in exchange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without having to provide her token in exchange at all, the other either tossed her own token at the researcher or out of the chamber, or refused to accept the slice of cucumber. Indeed, the mere presence of a grape in the other chamber (without an actual m&111nkey to eat it) was enough to induce resentment in a female capuchin.