考博试题

But it is a tough problem to approach. In looking for “life as we don’t know it”, it’s hard to even imagine what to expect.

Life might or might not exist on Mars. If there are critters there, they might or might not be like bacteria on Earth. In laboratory conditions, scientists in 2001 were able to get one-celled organisms to incorporate an amino acid---a fundamental building block of

life---that no other known life uses. The discovery borders on the creation of artificial life, experts said. It also suggests that ET might operate by entirely different rules than those we’re used to.

If life on Mars is fundamentally different from what scientists understand life to be, then current spacecraft and others in the works may well not recognize what’s right under their mechanical noses.

46. According to the text, we human beings are arrogant because

[A] we can send robots to Mars.

[B]we are searching ET in the outer space.

[C] we assume that life is all humanlike.

[D] we believe we are the most intelligent life.

47. According to Kenneth Nealson, scientists’ current approach to finding life is

[A] limited. [B]costly. [C] centralized. [D] earthly.

48. Nealson’s team’s discovery of extreme cases of life on Earth suggests that

[A] there might be life on Mars that still remains dormant.

[B]there might be ET in the universe that is like human beings.

[C] there might be life that is beyond the range of our current search.

[D] there might be ET elsewhere in the universe that does not require water.

49. The purpose of the author mentioning scientists’ laboratory creation in 2001 is to emphasize the idea that

[A] it is hard to imagine what ET is really like.

[B]life might or might not exist on Mars.

[C] it is possible to create artificial life.