单项选择题

It can be inferred from the passage that the gases of the Earth's atmosphere are contained by ______.

A．a closed surface
B．the gravity of the planet
C．the field of space
D．its critical point
<上一题 目录 下一题>
热门 试题

单项选择题
In Papousek's experiment babies make learned movements of the head in order to ______.
A．be praised
B．please their parents
C．be rewarded with milk
D．have the lights turned on
单项选择题
According to Papousek the pleasure babies get in achieving something is a reflection of ______.
A．the satisfaction of certain physiological needs
B．their strong desire to solve complex problems
C．a basic human desire to understand and control the world
D．a fundamental human urge to display their learned skills
相关试题