利用平方差公式计算:20132-2012×2014.
原式=20132-(2013-1)×(2013+1)
=20132-(20132-1)
=20132-20132+1
=1.
All the students will have a party ____ the afternoon of January 1.[ ]
A. in
B. on
C. at
D. for
涂料的备案申请在涂料进口至少2个月前向备案机构提出。()