![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
What does Werner J, A. Dahm say about the Hyper-X test flight?
A.
It was unsuccessful because it lasted only 11 seconds.
B.
It is a very important event in developing very fast airplanes.
C.
It allows people to fly at an altitude of 100,000 feet.
D.
It can transport cargo quickly and cheaply to outer space.