If someone spends his or her time, effort and money writing a book, for example, he or she deserves _______ for it.
A:paying
B:to pay
C:having been paid
D:being paid
①支持正常贸易
②反对鸦片走私
③反对开放口岸
④维护民族利益
已知x1、x2是方程2x2+3x-1=0的两个实数根,不解方程,求:①(x1-x2)2;②1x1+1x2的值.