D
It is hard to predict（预言）how science is going to turn out, and whether it is really good science, it is impossible to predict．If the things to be found are actually new, they must be unknown in advance．You cannot make choices on this matter．You either have science or you don’t and if you have it you have to accept the surprising and disturbing pieces of information, along with the neat and useful bits．
The only solid piece of scientific truth about which I feel totally confident is that we don’t know enough about nature．Indeed, I regard this as the major discovery of the past hundred years of biology．It is, in its way, a clear piece of news．It would have amazed the brightest minds of the 18th century to be told by any of us how little we know and how strange the way ahead seems．In earlier times, they either pretended to understand how things worked or simply made up stories to give answers．Now that we have begun exploring seriously, we are catching sight of how huge the questions are, and how far from being answered．Because of this, we are sorry．It is not so bad being ignorant（无知的）if you are totally ignorant; the hard thing is knowing in some details the reality of ignorance, the worst spots and here and there the not so bad spots, but no true light at the end of the tunnel nor even any tunnels that can yet be trusted．
But we are making a beginning, and there ought to be some satisfaction．There are probably no questions we can think up that can’t be answered, sooner or later．Within our limits, we should be able to work our way through to all our answers, if we keep at it long enough, and pay attention．
51．Acoording to the writer, really good science________．
A．would surprise the brightest minds of the 18th  century．
B．will help people to make the right choice in advance
C．will produce results which cannot be predicted
D．will bring about disturbing results
52．It can be inferred from the passage that scientists of the 18th century________．
A．thought that they knew a great deal and could deal with most problems of science．
B．knew that they were ignorant and wanted to know more about nature
C．were afraid of facing up to the realities of scientific research
D．did more harm than good in man’s understanding of nature
53．Which of the following is NOT mentioned about scientists in earlier times?
A．They falsely declared to know all about nature．
B．They did not believe in results from scientific observation．
C．They paid little attention to the problems they didn’t understand．
D．They invented false rules to explain things they didn’t understand．
54．What is the writer’s attitude towards science?
A．He is sorry because of the ignorance of scientists．
B．He is delighted because of the latest scientific findings．
C．He is doubtful because of the great difficulties in scientific research．
D．He is confident though he knows well the great difficulties in scientific research．
55．The writer believes that sooner or later________．
A．man can’t deal with all the problems he can find because of the limits of human knowledge．
B．man can find solutions to whatever questions concerning nature he can think up
C．questions concerning nature are outsiede the field of scientific research
D．man can think up all the questions and answer them all．