马克思一生最重要的理论发现是( )。A．无产阶级革命和无产阶级专政学说B．社会主义

太阳中含量最多的元素是氢和氦。氢元素和氦元素最本质的区别是

A．质子数

B．中子数

C．最外层电子数

D．核外电子数

While the examination is being carried out, ______ shall be present and responsible for moving the goods, opening and restoring the packing.

A. the consignee of the import goods and the consignor of the export goods
B. Customs officer
C. harbour officer
D. the owner of the ship

单元教学设计是在同一课题下一些互相关联的课堂计划的组合。

6°带和3°带的中央子午线是完全重合的。( )

脊柱向前弯曲时

A．椎间盘前方变厚
B．椎间盘前方变薄
C．椎间盘无任何变化
D．椎间盘侧方变薄
E．椎间盘向前移动