Electrical power is available up to the service ceiling of the airplane. What does "service ceiling" mean?
A.实用升限;
B.服务升限;
C.使用顶点;
D.服务天花板;
正确答案是A
Electrical power is available up to the service ceiling of the airplane. What does "service ceiling" mean?
A.实用升限;
B.服务升限;
C.使用顶点;
D.服务天花板;
正确答案是A