67. From the evolutionary point of view,__.

　　[A] forgetting for lack of practice tends to be obviously inadaptive .

　　[B] if a person gets very forgetful all of a sudden he must be very adaptive

　　[C] the gradual process of forgetting is an indication of an individual’ s adaptability

　　[D] sudden forgetting may bring about adaptive consequences

　　68. According to the passage, if a person never forgot,__.

　　[A] he would survive best

　　[B] he would have a lot of trouble

　　[C] his ability to learn would be enhanced

　　[D] the evolution of memory would stop

　　69. From the last paragraph we know that__.

　　[A] forgetfulness is a response to learning

　　[B] the memory storage system is an exactly balanced input-output system

　　[C] memory is a compensation for forgetting

　　[D] the capacity of a memory storage system is limited because forgetting occurs

　　70. In this article, the author tries to interpret the function of__.

　　[A] remembering

　　[B] forgetting

　　[C] adapting

　　[D] experiencing

　　[第67题答案及题解页数] D 第页