Book 5  Unit 1  Great Scientists預習學案

拓展：only if 可譯為“只有”
eg: only if you study hard, will you pass the test.
      make a call only if it is important.
5. the first suggested that cholera multiplied in the air.
  to prevent this from happening again, john snow suggested that the source of all the water supplies be examined.
   suggest 當暗示，表明時，從句用陳述語氣。
          當建議講時，從句用虛擬語氣 (should) ﹢do
  eg: i suggested that he give up smoking.
四.語法分析：過去分詞作定語和表語
課文原句：
1. he found that it came from the river polluted by the dirty water from london.
2. but he became inspired when he thought about helping ordinary people exposed to cholera.
過去分詞作定語：
意義：過去分詞含有被動和完成的意思，不及物動詞的過去分詞只表示完成
a broken heart
a ploughed field
a risen sun 已升起的太陽
位置：單個的過去分詞作定語時，通常放在所修飾詞前；過去分詞短語作定語時，通常放在后面。
polluted water
death caused by the accident
a broken glass
a glass broken by the boy
特別提示：
有些詞像left剩下的, given（所給的）, concerned（有關的） 等，習慣上作后置定語，如
 standing room left
 the people concerned  有關人士
 the book given  所給的書籍
當所修飾的詞是由some/ any /nothing/nobody…所構成的不定代詞或指示代詞those等時，通常放在其后。如：
there has been nothing changed since i left harbin two years ago.
區別：過去分詞作定語和現在分詞作定語
1. 語態不同：現在分詞表示主動，過去分詞表被動. 如
surprising news
surprised listeners
an exciting movie
excited children
the teacher told his students a lot of interesting stories.
she is interested in chinese.
2. 時間關系上不同：現在分詞表動作正在進行；過去分詞表動作已經完成。如
the changing world 正在發生變化的世界
the changed world  已經改變了的世界
boiling water
boiled water
developing countries
developed countries
過去分詞作表語：
意義：用在系動詞后面，構成系表結構，表示主語所處的狀態。
如 she looked disappointed.
   we were encouraged at the news.
用于被動語態，表示主語所承受的動作。如
  the book is well written.
  the lake is badly polluted.
五.單詞、短語突破
1. characteristic n.﹠adj.
  n.特征；特性
   what characteristics distinguish the americans and canadians?
  特有的，典型的 
 with the characteristic generosity, he offered to buy tickets for all of us.
2. conclude  vt. ﹠vi結束；推論出；議定，決定
 常用于以下結構：
conclude with sth.用……結束某事
conclude sth. from sth.從……推斷出