标题: 大全677 sunspots [打印本页] 作者: thornbirdcfa 时间: 2004-1-8 09:05 标题: 大全677 sunspots 4. Sunspots, vortices of gas associated with strong electromagnetic activity, are visible as dark spots on the surface of the Sun but have never been sighted on the Sun’s poles or equator. (A) are visible as dark spots on the surface of the Sun but have never been sighted on
(C) appear on the surface of the Sun as dark spots although never sighted at
为什么A错呢？be visible to sb as 是正确的短语啊！C的意思好像没有A通顺呢？ 谢谢～～～～～～～～～～～～～作者: shellyaaa 时间: 2004-1-8 11:04
留心最后的介词。作者: thornbirdcfa 时间: 2004-1-8 12:05
为什么不可以用on 要用at呢？ ：（作者: JerryGuan 时间: 2004-3-18 15:51
poles 是一点概念 所以用at作者: xjlv128 时间: 2006-6-10 09:24
用google搜，on,at the poles都有。估计这里强调“点“的概念作者: agnesliu 时间: 2010-7-25 10:10
同OG12-14 给的正确答案是A。所以你对的，大全答案错
