实地测定界址点坐标的方法有极坐标法、直角坐标法交会法和（）。
参考答案：内外分点法
Francis Presto Blair, Jr ______ born in Kentucky, lived and worked in Missouri. [ ]
A. was
B. he was
C. although
D. which was
“谷撒地，薯叶枯，青壮炼铁去，收禾童与姑，来年日子怎么过”，诗中反映的上世纪50年代末的现象，主要由于[ ]
A．经济建设缺乏经验
B．自然灾害迅速蔓延
C．左倾错误严重泛滥
D．苏联政府背信弃义
