gre阅读练习每日一篇(十)_GRE阅读

gre阅读练习每日一篇(十)

　　 In every culture studied, it was found that some forms of gift-giving are acts of aggression that place the receiver under obligation to the giver.

　　 Most governmental taxation systems differentiate between gifts of property given to children during a parents lifetime, and a childs inheritance of the same property from a parent dying without a will.

　　 Some gift-giving customs have analogous forms in nearly every culture, as in the almost universal custom of welcoming strangers with gifts of food.

　　 In North America, generally speaking, money is an acceptable holiday gift to ones letter carrier or garbage collector, but is often considered an insult if given to ones employer, friends, or relatives.

　　 Some gifts, being conciliatory in nature, indicate by their costliness the degree of hostility they must appease in the recipient.

　　Few areas of neurobehavioral research seemed more promising in the early sixties than that investigating the relationship between protein synthesis and learning. The conceptual framework for this research was derived directly from molecular biology, which had shown that genetic information is stored in nucleic acids and expressed in proteins. Why not acquired information as well?

　　The first step toward establishing a connection between protein synthesis and learning seemed to be block memory by interrupting the production of protein. We were fortunate in finding a nonlethal dosage of puromycin that could, it first appeared, thoroughly inhibit brain protein synthesis as well as reliably produce amnesia.