What does SAL stand for in this passage（）

A．Traveling in Space
B．Sleeping in the Spacecraft
C．Equipment Used by Astronauts
D．The Earth Seen from Outer Space

A．Forty minutes.
B．Fifty minutes.
C．Ninety minutes.
D．Twenty-four hours.

A．makes a bed
B．gets into his bag
C．listens to music
D．wears a sleep mask