79. Which of the following statements is NOT true according to the passage?
(A) Astronauts practice landing for hundreds of hours in a simulated space shuttle.
(B) Astronauts spend months getting accustomed to daily activities in zero gravity.
(C) The astronauts must be able to keep the space shuttle within 3 inches of the docking ring on the station.
(D) When the space shuttle glides toward the earth, its speed is more than 300 miles per hour.