They had to be launched into (25) ______________ with a big rocket which cannot be reused. Tomorrow's shuttles will take off and land on their own, probably like aeroplanes.
They had to be launched into (25) ______________ with a big rocket which cannot be reused. Tomorrow's shuttles will take off and land on their own, probably like aeroplanes.
A. plane
B. orbit
C. sky
D. atmosphere