题目内容：

    When people see machines that respond like humans, or computers that perform amazing feats of strategy, they sometimes joke about a future in which humanity will need to accept robot overlords. But buried in the joke is a seed of unease. Science fiction writing and popular movies have shown us about artificial intelligence (AI) that exceeds the expectations of its creators and escapes their control, eventually outcompeting and enslaving humans or targeting them for extinction(灭绝).

Even in the real word, not everyone is ready to welcome AI with open arms. In recent years, as computer scientists have pushed the boundaries of what AI can accomplish, leading figures in technology and science have warmed about the frightening dangers that artificial intelligence may pose to humanity, even suggesting that AI capabilities could destroy the human race.

But why are people so frightened about the idea of AI?

Elon Musk is one of the famous voices that have raised red flags about AI, In July 2017. Musk told attendees at a meeting of the National Governors Association, I have exposured to the very cutting-edge Al,and I think people should be really concerned about it.I keep sounding the alarm bell. But until people see robots going down the street killing people, they don't know how to react, because it seems so impossible."

Earlier, in 2014, Musk had labeled AI "our biggest existential threat," and in August 2017, he declared that humanity faced a greater risk from AI than the terrorists. Physicist Stephen Hawking, who died on March14, also expressed concerns about AI, telling the BBC in 2014 that "the development of full artificial intelligence could spell the end of the human race.

1.What are top scientists in AI worried about?

A. Its ability of impressive fests. B. It contributes too much to movies.

C. It may end the human race some day. D. It's capability to bury our seeds in jokes.

2.What is "red flags" in paragraph 4?

A. Questions. B. Warnings

C. Complaints. D. Wonders.

3.In Stephen Hawking' opinion, AI could_____

A. be a great threat to human beings. B. learn the human emotions like fear,

C. predict the future of the human race. D. compose horrible tales into scary stories.

4.The text is probably taken from a research paper in____

A. Technology B. Health

C. Planet earth. D. Human nature.