ㄟ...............
這段英文沒有講到『從太陽來的asteroids命中南半球的機率比北半球小』吧 :)

Second,if an asteroids is coming from the direction of the sun,
it cannot be seen because the sun is too bright.
如果小行星是從太陽的方向過來，因為太陽太亮，所以我們會看不到它

Finally,thereis no large-scale program in the southern hemispthere
to try to find asteroids.
南半球沒有大型的小行星觀測計畫

"旅人" <assddd0206.bbs@ptt.cc> 撰寫...
> 這是我的英文課本的其中一段話
> Today,the governments of serveral countries try to locate
> NEAs(near-Earth asteroids).  Universit and amateur astronomers
> also watch out for dangerous asteroids.  However,there are problems.
> First,most asteroids are small and dark. That makes then difficult
> to spot. Second,if an asteroids is coming from the direction of
> the sun,it cannot be seen because the sun is too bright.
> Finally,thereis no large-scale program in the southern hemispthere
> to try to find asteroids.
> 中間說的又黑又小所以不好找這還理解
> 不過後來說的”從太陽來的asteroids命中南半球的機率比北半球小”
> 這就不太清楚了
> 是因為南半球的面積比較少這樣而以嗎？
> 還是還包含地球傾斜的角度、形狀(橢圓形)...等
> 或者還有其他理由呢？
> 請內行解答，謝謝！