The dress is very nice. Can I try it ______ ? [ ]
A. out
B. in
C. on
D. away
答案:C
当a=-1,b=1时,(3a2-2ab+2b2)-(2a2-b2-2ab)=( ).
无缝线路应力放散时,每隔100-200米设置应力放散点达到放散均匀。