LZ做到的只有后2段,一个问文章的主要目的,一个问文章的结构,一个问削弱最后一段的第一句里的evident的。还有一个,绕了一大圈,问那些旋转的速度快得足以让行星fly apart的小行星一定是以下哪一种(囧,表达不能)。LZ的思路是这样的:If nearly all asteroids are rubble piles, however, this tail would be missing, because any rubble pile spinning faster than once every two or three hours (depending on its bulk density) would fly apart.因为行星们都不能旋转太快,否则他们会fly apart,又Alan Harris of the Jet Propulsion Laboratory in Pasadena, Calif., Petr Pravec of the Academy of Sciences of the Czech Republic in Prague and their colleagues have discovered that all but five observed asteroids obey a strict rotation limit。 The exceptions are all smaller than about 150 meters in diameter, with an abrupt cutoff for asteroids larger than about 200 meters. 所以,那些旋转得那么快,又不会fly apart的,就是那些BUT FIVE,既那些exceptions了,所以选smaller than about 150 meters in diameter 应该没错吧,还是请N人确定一下。 或者是不是这篇 -- by 会员 bywang (2012/9/25 11:02:03)
这是神马这是神马~~~ |