The space shuttle ______ broke apart and burned up while reentering Earth's atmosphere in 2003.

A．To spend less time at their telescopes.
B．To overcome the problem of weak light.
C．To take more photographs.
D．To photograph astronomical objects without using a telescop

A．They spend most of their time looking through telescopes.
B．They are constantly analyzing data.
C．They often live near observatories.
D．They devote a lot of time to theoretical problems.