Have you ever had the strange feeling that you were being watched? You turned around and, sure enough, someone was looking right at you!
Parapsychologists（灵学家）say that humans have a natural ability to sense when someone is looking at them. To research whether such a “sixth sense” really exists, Robert Baker, a psychologist（心理学家）at the University of Kentucky, performed two experiments.
In the first one, Baker sat behind unknowing people in public places and stared at the backs of their heads for 5 to 15 minutes. The subjects（受试者）were eating, drinking, reading studying, watching TV, or working at a computer. Baker made sure that the people could not tell that he was sitting behind them during those periods. Later, when he questioned the subjects, almost all of them said they had no sense that someone was staring at them.
For the second experiment, Baker told the subjects that they would be stared at from time to time from behind a two way mirror in a laboratory setting. The people had to write down when they felt they were being stared at and when they weren’t. Baker found that the subjects were no better at telling when they were stared at and when they weren’t. Baker found that the subjects were no better at telling when they were started at than if they had just guessed.
Baker concludes that people do not have the ability to sense when they’re being stared at. If people doubt the outcome of his two experiments, said Baker, “I suggest they repeat the experiments and see for themselves.”
68. The purpose of the two experiments is to        .
A. explain when people can have a sixth sense
B. show how people act while being watched in the lab
C. study whether humans can sense when they are stared at
D. prove why humans have a sixth sense
69. In the first experiment, the subjects       .
A. were not told that they would be stared at
B. lost their sense when they were stared at
C. were not sure when they would be stared at
D. were uncomfortable when they were stared at
70. The underlined word “outcome” in the last paragraph most probably means      .
A. value  B. result  C. performance      D. connection
71. What can be learned from the passage?
A. People are born with a sixth sense.
B. The experiments support parapsychologists’ idea.
C. The subjects do not have a sixth sense in the experiments.
D. People have a sixth sense in public places.