D
What's your earliest childhood memory? Can you remember the first time you heard thunder or watched a television program? Adults seldom recall events much earlier than the year or so before entering school, just as children younger than three or four rarely retain any memory of specific, personal experiences.
A variety of explanations have been proposed by psychologists for this "childhood amnesia"( 记忆缺失,健忘).One argues that the hippocampus, the region of the brain which is responsible for forming memories, does not mature（成熟）until about the age of two. But the most popular theory maintains (主张）that, since adults do not think like children, they cannot access childhood memories. Adults think in 
words, and their life memories are like stories. But when they search through their mental files for early childhood memories to add to this verbal life story, they don't find any that fit the pattern. It's like trying to find a Chinese word in an English dictionary.
Now psychologist Annette Simms offers a new explanation for childhood amnesia. She argues that there simply aren't any early childhood memories to recall. According to Dr. Simms, children need to learn to use someone else's spoken description of their personal experiences in order to turn their own short-term, quickly forgotten impressions of these experiences into long-term memories. In other words, children have to talk about their experiences and hear others talk about them - Mother talking about the afternoon spent looking for crabs(蟹) at the beach or Dad asking them about their day at Ocean Park. Without this verbal reinforcement, says Dr. Simms, children cannot form permanent memories of their personal experiences.
69. According to the passage, it is widely believed that_________.
A. it is impossible for an 
adult to recall his(or her) childhood experiences
B. adults virtually have no access to their childhood memories
C. adults think in words while children think in images
D. adults and children have different brain structures
70. "Trying to find a Chinese word in an English dictionary" is stated in the passage to show that_______.
A. Chinese and English are totally different languages
B. it is unlikely to find a Chinese word in an English dictionary
C. adults and children have different memory patterns
D. memories are in some way connected with languages
71. According to Annette Simms,_______________.
A. verbal reinforcement is necessary for children to have permanent memories
B. there does not exist such things as childhood memories
C. children's brains are mature enough to form permanent memories
D. children are generally inexperienced and unable to remember things they don't understand
