すみません、、、下記の問題でDが答えらしいのですが、根拠がなんなのか分かりません。。。 A useful informationの話はしていない B people are interested in exploringが減った話はない C recent developments have made exploration less exciting.の話はしていない と思って消去法的にDを選んだのですが、、、 ln the fourth paragraph, the writer refers to 'a golden age'to suggest that A the amount of useful information produced by exploration has decreased. B fewer people are interested in exploring than in the 19th century. C recent developments have made exploration less exciting. D we are wrong to think that exploration is no longer necessary. ＜ln the fourth paragraph＞ In this book about the exploration of the earth's surface, I have confined myself to those whose travels were real and who also aimed at more than personal discovery. But that still left me with another problem: the word 'explorer' has become associated with a past era. We think back to a golden age, as if exploration peaked somehow in the lgth century - as if the process of discovery is now on the decline, though the truth is that we have named only one and a half million of this planet's species, and there may be more than 10 million - and that's not including bacteria. We have studied only 5 per cent of the species we know. We have scarcely mapped the ocean floors,and know even less about ourselves; we fully understand the workings of only 10 percent of our brains.