______ of that country is covered by snow.
A:Second thirds
B:Two thirds
C:Twos thirds
D:Two third
如图所示是某同学绘制的部分磁感线分布示意图,根据图示,以下分析正确的是( )
①土地改革;②人民公社化;③农业合作社;④家庭联产承包责任制;