According to the passage, why was John Glenn's flight considered so successful?A.It was th
According to the passage, why was John Glenn's flight considered so successful?
A.It was the first time a rocket had reached orbit and returned.
B.NASA had finally learned how to stay in orbit for a long time.
C.The astronauts were able to move outside the spacecraft.
D.He was able to land on the Moon's surface for the first tim