下列说法中正确的是[ ]
A.绝对值等于其本身的数是0和1
B.有理数分为整数、零和分数
C.如果两个数的绝对值相等,则这两个数相等
D.互为相反数的两个数的绝对值相等
答案:D
People in developed countries are supposed ____ more healthy food before than what they have today.
A.to be had
B.to have
C.had
D.to have had
机械加工工艺过程是由按一定顺序安排的工序组成的。( )