元素的化学性质主要取决于原子的（　　）

A．最外层电子数

B．核内质子数

C．核外电子总数

D．相同原子质量

Guide tolerances during elevation of the jack-up rig will（）.

A.reduce spud can bearing pressure

B.keep the unit level and reduce overloading

C.reduce stresses on the hull

D.minimize the potential for punch-through