Dr. Peter Spence, _____ headmaster of the school, told us, "_____ fifth of pupils here go on to study

at Oxford and Cambridge." [ ]

A. 不填; A

B. 不填; The

C. the; The

D. a; A

下面程序段中的循环体的执行次数是( )。 for(i=4；i＜0；i--) for(j=1；j＜=4；j++) sum=sum+j；

A．4

B．0

C．12

D．16