原式=(-2)2+(-3 )2=4+9=13.
More and more students are going to have Friday afternoons________ to volunteer and help others.
A.at
B.in
C.on
D.off
近几年我国数次上调了个税起征点。提高个人所得税起征标准,将有利于
A.调节个人收入,实现社会公平
B.增加财政收入
C.完善我国的社会保障制度
D.抑制过高收入