[討論]Fei Fei- 39 (135道題裡)

[Wassermann]

39. Quasars---celestial objects so far away that their light takes at least 500 million years to reach Earth---have been seen since 1963. For anything that far away to appear from Earth the way quasars do, it would have to burn steadily at a rate that produces more light than 90 billion suns would produce.But nothing that burns at a rate that produces that much light could exist for more than about 100 million years.

If the statements above are true, which one of the following must also be true on the basis of them?

(A) Instruments in use before 1963 were not sensitive enough to permit quasars to be seen.
(B) Light from quasars first began reaching Earth in 1963.
(C) Anything that from Earth appears as bright as a quasar does must produce more light than would be produced by 90 billion suns.
(D) Nothing that is as far from Earth as quasars are can continue to exist for more than about 100 million years.
(E) No quasar that has ever been seen from Earth exists any longer.


答案：E
思路：
A：可能足夠sensative，只是沒有觀察到而已。
B：同樣只是沒有觀察到而已。
C：沒有定義與地球的距離。
D：沒有定義亮度
E：原文實際認為現在看到的來自Quasars的光是500萬年前發出的。而在400萬年前這些類星體就已經燃盡不存在了。

Choice C 裏, 解釋說題幹沒定義, 但我看題幹有敍述到.
不知是否有哪位大大知道 choice C 錯的原因為何?

[維尼]

麻煩貼出答案選項吧... :)

[Wassermann]

不好意思~~~~
我重新編輯把選項貼出來了~~~
望NN 幫忙~~~

[維尼]

我覺得答案C提到 一樣亮
原文似乎沒有提到亮度大小的問題耶

[Wassermann]

TKS 維尼~~~
我再細細品味一下這道題~~:P