例题1:It is not known why Americans are more mobile than most others are, but one possibility relates to the lower levels of company training received by American workers. Another possibility, however, is that the costs of mobility are lower in the United States (despite the fact that Japan and Europe are more densely populated and hence more urban). What would create these lower costs?

问： According to paragraph 3, what is one possible explanation for why American workers change jobs more frequently than workers elsewhere do?

A.The relatively small percentage of American workers who live in urban areas.

B.The tendency of American employers to provide less training for workers

C.The recent decrease in mobility costs in the United States

D.The lower average population density in the United States

例题2: Three other explanations seem more promising. One involves physiological changes relevant to memory. Maturation of the frontal lobes of the brain continues throughout early childhood, and this part of the brain may be critical for remembering particular episodes in ways that can be retrieved later. Demonstrations of infants’ and toddlers' long-term memory have involved their repeating motor activities that they had seen or done earlier, such as reaching in the dark for objects, putting a bottle in a doll’s mouth, or pulling apart two pieces of a toy. The brain’s level of physiological maturation may support these types of memories, but not ones requiring explicit verbal descriptions.

问： What does paragraph 3 suggest about long-term memory in children?

A.Maturation of the frontal lobes of the brain is important for the long-term memory of motor activities but not verbal descriptions.

B.Young children may form long-term memories of actions they see earlier than of things they hear or are told.

C.Young children have better long-term recall of short verbal exchanges than of long ones.

D.Children’s long-term recall of motor activities increases when such activities are accompanied by explicit verbal descriptions.