A. north B. for his trip C. in the future D. sour lemons E. school uniforms F. go to the park
先化简,再求值:(x﹣y2)﹣(x﹣y)(x+y)+(x+y)2,其中x=3,y=﹣ 13 .
计算1+2014(11+2+12+3+13+4+…+12013+2014)