On July 20, 1969, the dream to visit the moon came true. Two American astronauts landed on their names were Neil Armstrong and Edwin Aldrin.
The first thing the men discovered was that the moon is covered with gray dust. The dust is so thick that the men left footprints wherever they walked. Those were the first footprints any living thing had ever made on the moon. And they could stay there forever! There is no wind or rain to wipe them away.
The two astronauts walked on the moon for four hours. They picked up rocks for earth scientists to study. They dug up dirt to bring back to earth. They set up machines to find out things scientists wanted to know. Then they climbed back into their moon-landing craft.
The next day the landing-craft rockets roared as the two men blasted off from the moon. They joined Michael Collins in the space ship that waited for them above the moon. Then, they began the long trip back to earth. Behind them they left the craters, plains, and tall mountains of the moon. They left the machines they had set up. And they left footprints that may last forever.
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“They joined…..in the space ship that waited for them above the moon”. (p.4)
What the word “them” in the sentence refer to?
A. Neil Armstrong and his three crews
B. Edwin Aldrin and his Michael Collins
C. Michael Collins and all his friends
D. Neil Armstrong and Edwin Aldrin