謂語動詞的強調
①. It is/ was ... that ... 結構不能強調謂語，如果需要強調謂語時，用助動詞do/ does或did
Do sit down. 務必請坐。
Do be careful when you cross the street. 過馬路時，務必(千萬)要小心啊!
②此種強調只用do/ does和did，沒有別的形式過去時用did，後面的謂語動詞用原形。
強調形式
常見到的強調形式，共有以下七類：
⒈用dodoesdid + V可表強調
Some people do believe that nuclear power poses a threat to the world peace.
⒉adv或adj可表強調：Never only Very
This is the very question that deserves careful analysis.
