问题详情

What did Werner J.A Dahm of the University of Michigan say about the Hyper-X test flight？
A．It indicated the birth of a very fast airplane.
B．It was self-powered, so it lasted only 11 seconds.
C．It can transportcargo quickly and cheaply to the brink of space.
D．It is a major milestone in the journey of making a new type of very fast airplanes.请帮忙给出正确答案和分析，谢谢！