要不要 "it"的問題:
    先看兩個句子：
    We sometimes find it difficult to get rid of a bad habit. (有時(shí)我們發(fā)現(xiàn)要改掉一個壞習(xí)慣很難。)該句的原始結(jié)構(gòu)可理解為：We sometimes find (to get rid of a bad habit) difficult. 括號部分(動詞不定式)為賓語，difficult為賓語補(bǔ)足語
    The doctor has made it clear to you that there is nothing wrong with your stomach.(醫(yī)生已經(jīng)跟你說得很清楚了，你的胃沒有什么問題。)該句的原始結(jié)構(gòu)可理解為：The doctor has made (there is nothing wrong with your stomach)clear. 括號部分(句子)為賓語，clear為賓語補(bǔ)足語
    歸納：
    n 在主語 + 賓語 + 賓語補(bǔ)足語結(jié)構(gòu)中，當(dāng)賓語是"動詞不定式"或"句子"時(shí)，要用it(不是this, that或其他任何詞)作形式賓語，將動詞不定式或句子移到句子的后面去。
    n 考試時(shí)，判斷要不要 "it"，主要看句子后面有沒有"動詞不定式"或"句子"，若有，要選 "it"
    n 賓語、賓語補(bǔ)足語倒裝：當(dāng)賓語(名詞)較長，賓語補(bǔ)足語較短(往往是1個形容詞，如possible, impossible, difficult, easy, clear等)時(shí)，為了句子結(jié)構(gòu)均衡，往往采用倒裝，這里不存在"it"的使用問題, 對下句作出判斷：
    The development of ultrasound has made ______ early diagnosis of some fatal diseases. (超聲波的出現(xiàn)使許多致命疾病的早期診斷成為可能。)
    A. it possible
    B. possible
    C. it is
    D. it
    該題的正確答案應(yīng)為B，因?yàn)榫渥硬捎昧说寡b形式，原結(jié)構(gòu)為：
    The development of ultrasound has made [early diagnosis of some fatal diseases] possible.
    賓語 補(bǔ)足語
    3) 記住以下短語：
    to take…as(把…當(dāng)作…)
    to think of…as(把…看作…)
    to regard…as(把…看作…)
    to refer to…as(把…叫作…)
    關(guān)于五個基本句型，重點(diǎn)要掌握每個句型的出題點(diǎn)，舉一反三。