36套EX3Q2

HardyNiborUID: 3461489

吀栀攀 dark regions in the starry night sky are not
pockets in the universe that are devoid of stars as
had long been thought. Rather, they are dark because
Line of interstellar dust that hides the stars behind it.
5 Although its visual effect is so pronounced, dust is
only a minor constituent of the material, extremely
low in density, that lies between the stars. The average density of interstellar material in the vicinity of our Sun is 1,000 to 10,000 times less than the best terrestrial
10 laboratory vacuum. It is only because of the enormous interstellar distances that so little material per unit of
volume becomes so significant. Optical astronomy
is most directly affected, for although interstellar gas
is perfectly transparent, the dust is not. (125 words)

2. It can be inferred from the passage that it is
because space is so vast that
(A) little of the interstellar material in it seems substantial
(B) normal units of volume seem futile for measurements
of density
(C) stars can be far enough from Earth to be obscured
even by very sparsely distributed matter
(D) interstellar gases can, for all practical purposes, be
regarded as transparent
(E) optical astronomy would be of little use even if no
interstellar dust existed

这个题上个月有帖子说了具体的定位，“ It is only because of the enormous interstellar distances that so little material per unit of volume becomes so significant. ” 对应“stars can be far enough from Earth to be obscured even by very sparsely distributed matter”

可是这两句是不是结论相反呢？一个说单位空间里这么少的物质亮了，一个说单位空间里这么少都看不见。

或者是我理解错了，求指教，谢谢。

Leon-WangUID: 2772364

第一句你理解错了，第一句强调的是enormous interstellar distances导致这么稀疏的物质变得非常重要。就是说，虽然这个dust很稀疏，但是距离太远，那么这么多点点就叠加在一起就挡住了。所以没有矛盾。

HardyNiborUID: 3461489

Leon-Wang 发表于 2013-9-3 23:00
第一句你理解错了，第一句强调的是enormous interstellar distances导致这么稀疏的物质变得非常重要。就是说 ...

词汇不过关，打脸