After 20 years of marriage, a husband may still not understand his wife. How is it that she is never at a 1 for words How can she 2 the names of a couple they met on 3 years ago Now we know 4 to tell him: It"s her brain.Although there are obviously cultural 5 for the differences in emotions and behavior, 6 breakthrough research reveals that the 7 of many puzzling differences between men and women may 8 in the head. Men"s and women"s brains 9 much in common, but they are definitely not the same 10 size, structure or insight. Broadly speaking, a woman"s brain, like her body, is ten to fifteen percent smaller than a man"s, 11 the regions dedicated to the language may be more densely 12 with brain cells.Girls generally speak earlier and read faster. The reason may be 13 females use both sides of the brain when they read. In 14 , males rely only on the left side.At every age, women"s memories 15 men"s. They have a greater ability to 16 names with faces than men do, and they are 17 at recalling list. The events people remember best are those that an emotion is attached to. 18 women use more of their right brains, which 19 emotions, they may do this automatically.While we don"t yet know what all these findings imply, one thing is 20 : Male and female brains do the same things, but they do them differently.

A. when
B. how
C. what
D. where