第一段詞匯解析
    ①detect = discover, find。
    ②in relative terms = relatively (speaking) , in relation to other things。
    ③emit = send out。
    ④ideal conditions = an environment which is perfect (for the development of life)。
    第二段詞匯解析
    ①capable of = able to。
    ②alternatively = on the other hand。
    ③presence = existence。
    第三段詞匯解析
    ①在 because 引導(dǎo)的原因狀語從句中還有一個“ the further…system”作比較狀語從句。
    ②小綠人這個單詞本身在英語語境中就是指代外星人，是想象的外星小綠人。
    Notes 學(xué)習(xí)筆記
    詞組歸納
    1.Milky Way
    2.in relative terms
    3.solar system
    4.far too
    5.depend on
    6.up to
    7.life forms
    8.at present
    9.in existence
    10.be capable of
    11.Hubble telescope
    12.because of
    13.dust particles
    14.look for
    15.outer space
    16.outer edge
    17.blot out
    18.in the first instance
    19.little green men
    20.in the realms of sth.
    21.science fiction