The reason for the division of Class E and Class A airspace stems from the type of planes operating in them.
E 类和 A 类空域的划分取决于在这两类空域飞行的飞机类型。
2
It may represent a new class of failed stars straddling the division between stars and Jupiter-like planets.
它可能代表了一类新的“失败之星”，即介于恒星和类木行星之间的一种星体。
3
The most important division, however, is probably between the middle class created by the actions of the state and its equivalent created by its own efforts in the private sector.