引起胎儿窘迫最常见的原因是A．PIH B．脐带脱垂 C．脐带先露 D．胎盘功能不良

The Shengzhou VI aircraft carried two astronauts into____sky at 9:00 am on October 12, 2005 and the two astronauts will stay in _____space for five days.

A．a; the

B．the; 不填

C．the; the

D．a; 不填

有机磷农药中毒时，应用解磷定或双解磷定，其原理是

A．直接兴奋大脑

B．恢复胆碱酯酶活性

C．解除迷走神经兴奋

D．解除交感神经兴奋

E．使椎体束兴奋

读下表，分析回答：

（1）我国自然资源方面的基本特点是什么？                                                                                                                                                                （2）请比较中国、美国、日本、加拿大四国在自然资源方面的差异。                                                                                                                                                                                                                                                                                                                              （3）怎样对待我国人均资源不足的问题？                                                                                                                                                              

常见的地图编号方式有（）。

A.方里网编号

B.任意编号

C.经纬线编号

D.自然序数编号

E.行列式编号