18. How will CEV and the moon lander be launched?
A. They will be launched separately.
B. CEV will dock with the moon lander.
C. They will be launched together.
D. The moon lander will hold four astronauts.

19. What will be the astronauts’ top priorities?
A. Entering the orbit and landing on the moon.
B. Landing and walking on the moon surface.
C. Exploration and researches into the moon composition.
D. Exploration and construction of a moon base.

20. The reason why NASA hopes to carry out at least two moon missions a year stating in 2018 is to ____.
A. ensure the moon traveling and the moon base construction
B. speed up the moon base construction and other activities
C. guarantee the quality of the researchers’ scientific study
D. set up new training laboratories for future missions to Mars

Questions 21-25 are based on the following passage:
At the end of the U.S. Civil War, about 4 million slaves were freed. Now, people around the world can hear some of the former slaves’ stories for the first time ever, as told in their own voices.
“That was in slavery time,” says Charlie Smith in one interview. “They sold the colored people. And they were bringing them from Africa. They brought me from Africa. I was a child.”
The Library of Congress released the collection of recordings, Voices from the Days of Slavery, in January. The recordings were made between 1932 and 1975. Speaking at least 60 years after their emancipation (解放), the strorytellers discuss their experiences as slaves. They also tell about their lives as free men and women.
Isom Moseley was just a by at the time of emancipation, but he recalls that things were slow to change. “It was a year before the folks knowed they was free,” he says.
Michael Taft, the head of the library’s archive of folk culture, says the recordings reveal something that written stories cannot. “The power of hearing someone speak is so much greater than reading something from the page,” Taft says. “It’s how something is said---the dialect, the low pitches, the pauses---that helps tell the story.”

21. What is new about the slaves’ stories?
A. They are told in the slaves’ own voices.
B. People travel around the world to hear them.
C. Colored people were sold.
D. They happened in the slavery time.

22. What is the title of the collection of recordings?
A. The End of the U.S. Civil War.
B. The Library of Congress
C. Voices from the Days of Slavery.
D. The Recordings of Written Stories.

23. How many years did it take to complete the collection of recordings?
A. 26 years.                               B. 33 years
C. 44 years                                D. 57 years.