NASA had planed to launch its space shuttle ______ in September.

A．That it can't be measured.
B．That it doesn't change.
C．That it's getting smaller.
D．That it's rapidly increasin

A．Being too prudent and cautious.
B．Being too hasty to assure safety.
C．Causing the Columbia tragedy.
D．Delaying launch plans.

A．Why stars move so quickly.
B．Why few stars have planets.
C．Why stars aren't moving toward one another.
D．Why stars haven't moved farther apart.