A、They were severely punished. B、They were treated well. C、They were sold to another white man. D、They were given different work

The African ancestors of today’s black Americans were brought to the U.S. as slaves in the seventeenth, eighteenth, and nineteenth centuries. They worked on farms, especially the large farms in the southern states. Slowly they became a necessary part of the economic system of the South.
Slaves did not have the rights of people, according to the law, they were “things” which belonged to the person who bought them .They had to obey the orders of their owners without question. (16) They were not allowed to learn to read, because their owners feared that educated slaves would begin to think about the injustice of the system and would learn to struggle for their freedom. Slaves had to work long hours in extremely unhealthy conditions.
Their owners had complete power over them. They could be bought and sold like animals. At the slave markets, black children separated from their parents and never saw them again. (17) Slave owners had the right to punish severely any slave who broke rules or protested against the system. Slaves were often beat brutally by their owners or killed. After the Civil War, one free slave reported that his owners killed an older slave who was teaching him to read.
There was a law against brutality to slaves, so in theory an owner who treated a slave badly could be punished. In practice, however, the law meant nothing.
(18) Another law said that slaves could not give evidence against white people, so very few owners were ever punished for their brutality.
Questions 16 to 19 are based on the passage you have just heard.
16. Why couldn’t slaves learn to read?
17. What happened to slaves who broke the rules of the system?
18. How was the condition of the slaves after the Civil War?
19. What can we infer from the passage?