A:14026
B:π4026
C:12013
D:π2013
如图1所示,电线杆的铁丝拉线上M、N、P三处,最容易生锈的地方是
__________ they are twins, they don't look the same at all.
树上原来有4只小鸟,飞来2只,现在有____只;又飞来2只后,一共有____只。