中国历代首都移动轨迹的支流是（）。
A.东西之间，由西而东
B.东西之间，由东而西
C.南北之间，由北而南
D.南北之间，由南而北
参考答案：C
The climate change conference has come to __________ end, but the developing countries are
dissatisfied with __________ small step that the developed countries have taken to reduce the
emission (排放) of water gases.[ ]
A. 不填, a
B. 不填, the
C. an , a
D. an, the
试分析仰斜开采的特点及使用条件。
