Read the text and answer questions 46 to 50.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.
46. What is the text about?
A. Two men who successfully landed on the moon.
B. The moon-landing craft used by astronauts.
C. People’s visits to the space through t he moon
D. The craters, plains and mountains third of the moon

47. What does the third paragraph tell you about?
A. Taking a walk on the surface of the moon
B. The first moon-landing craft
C. The astronaut’s activities on the moon D. The research done by earth scientists

48. Neil Armstrong’s footprints could stay forever on the moon because
A.They are made of hard rock of the moon
B. They were set up by machines and strong dirt
C. They were placed on the tall mountains of the moon
D. There is no wind or rain to wipe them away

49. Based on the text, it can be concluded that the situation in the moon is very…
A. Noisy      C. Common
B. Quiet      D. Crowded

50. “And they left footprints that may last forever”. What does the word “forever” mean?
A. For all future time       C. In the long run B. In the near future       D. For the time being​