在地球表面上，决定太阳直射最北和最南界线的是[ ]
A、地球的自转运动
B、地球的球体形状
C、地球在宇宙中的位置
D、黄赤交角的大小
答案：D
John had made up his mind to give it up, but on _________ second thought he determined to have __________ third try.
A．/ ; /
B． a; a
C．the; a
D．/ ; a
如何理解心与肺、脾的关系?
