Robots make me nervous-especially the ones which seem to think for themselves．I was embarrassed to admit this till I heard that Bill Gates，the founder of Microsoft，felt the same way．Gates said in an interview with the website Reddit：“I am in the camp that is concerned about super intelligence．First the machines will do a lot of jobs for us and not be super  intelligent．That should be positive if we manage well．A few decades after that though the intelligence is strong enough to be a concern．”
Well，maybe I don’t have to worry about my laptop and kitchen appliances yet．After I  use them I can always pull the plug．But in the future，machines might find a way to prevent  us from switching them off．There’s a scary thought!
Professor Stephen Hawking warned a few months ago about the possibility that artificial intelligence could evolve and end up beyond human contro1．He suggested that machines could“spell the end of the human race”．
Maybe the problem with computers too clever for us is not that they are evil or rebellious．What could put us in danger is that they might be too efficient．That’s what philosopher Nick Bostrom from the Future of Humanity Institute at Oxford University believes．He says that machines are indifferent to humans and in pursuit of their own goals，the destruction of people might be just collateral(附带的)damage．A machine would not take pity on you．
I’m glad my machines at home are“dumb”．All my vacuum cleaner wants to take over is the carpet in my living room．Let’s hope they don’t create an appliance which wants to take over the world!
We can conclude from Gates’statements that ___________．

A．he is embarrassed that he is afraid of robots

B．he doesn’t think machines are intelligent

C．machines should be fully employed

D．machines’super intelligence should be a concern

The underlined word“spell”in Paragraph 3 is closest in meaning to _____________．

A．record

B．cause

C．explain

D．develop

Why are computers dangerous according to Nick Bostrom?

A．They are too evil and rebellious．

B．They are indifferent to humans．

C．They show pity on humans.

D．They are too clever and efficient．

What can be inferred about the author?

A．He doesn’t agree with Bill Gates．

B．He is not content with the present kitchen appliances．

C．He is scared about the super intelligence of machines．

D．He expects that machines will take place of humans．