A.the truth is __56___

B.but must be coaxed into  57  

C.is a prerequisite  58  

Of course,  59  .This century, the work of cognitive psychologists has illuminated the subtle forms of daily learning on which intellectual progress depends.Children were observed as they slowly grasped——or ,as the case might be, bumped into——concepts that adults take for granted that quantity is unchanged as water pours from a short glass into a tall thin one.Psychologists have since demonstrated that young children, asked to count the pencils in a pile, readily report the number of blue or red pencils,  60  .Such studies have suggested that the rudiments(基本原理) of mathematics are mastered gradually, and with effort.They have also suggested that the very concept of abstract numbers—— the idea of a oneness, a twoness, a threeness that applies to any class of objects  61  more mathematically demanding than setting a table—— is itself far from innate.