例題4(1997年8月考題)Unlike fossil fuels, which can be used only once, wind and solar power _____of energy.

(A) for renewable sources
(B) the sources are renewable
(C) are renewable sources
(D) renewable sources

這里，句子的主干應該是wind and solar power____ of energy。Unlike fossil fuels表示比較，做狀語。而which引導的從句which can be used only once修飾fossil fuels。我們將4個選項分別代入句子主干的空格中，得(A) wind and solar power for renewable sources of energy選項A沒有主語，即沒有完整的主謂結(jié)構(gòu)。(B) wind and solar power the sources are renewable of energy很明顯，這也不能構(gòu)成一個完整的有意義的句子。(C) wind and solar power are renewable sources of energy這個選項最合適，因為主謂齊全，而且以名詞sources結(jié)尾，讓介詞短語of energy修飾。(D) wind and solar power renewable sources of energy很明顯，這也不能構(gòu)成一個完整的主謂結(jié)構(gòu)。所以，正確答案是C��

例題5(1997年8月考題)Today _____ of the Earth live on a very small percentage of the Earth's land surface.

(A) about two-thirds populated
(B) the population is about two-thirds
(C) about two-thirds of the population
(D) of about two-thirds the population is

首先，分析句子結(jié)構(gòu)。根據(jù)句子的大意，動詞live應該是主句的謂語動詞。空格填入的應該是句子的主語，而a very small percentage of修飾限定the Earth's land surface。我們簡化這個句子，得出句子主干_____ live on the Earth's land surface�？崭駜�(nèi)應該填入名詞或者名詞短語。4個選項中，只有C是明顯的名詞短語，代入后也符合句意。選項A中的populated不論是做定語還是謂語都不符合句意。而選項B和D都是帶有助動詞的主謂結(jié)構(gòu)，當然不能填入只缺主語的句子中。所以，正確答案是C�，�

例題6(1997年8月考題)Following the guidelines for speaking and voting established by the book Robert's Rules of Order, _____during meetings.

(A) and avoid large decision-making organizations' procedural confusion
(B) large decision-making organizations avoid procedural confusion
(C) is procedural confusion avoided by large decision-making organizations
(D) are avoiding procedural confusion in large decision-making organizations

首先，我們分析following以后空格以前句子的成分。其中的established by the book Robert's Rules of Order和for speaking and voting都修飾the guideline。所以，我們可以將空格前的成分簡化為following the guidelines。那么這時，原句成為Following the guidelines, _____ during meeting.和例題3一樣，following the guidelines不是做定語(伴隨狀語)就是做謂語。如果它做定語，后面必須帶自然語序的主謂結(jié)構(gòu)；如果它做謂語，后面必須帶倒裝的主謂結(jié)構(gòu)。

由此，我們排除帶有and的選項A。根據(jù)句意(guidelines和confusion的意思)我們又可以排除選項C。這時，我們只剩下選項B和D。選項D是主謂倒裝的結(jié)構(gòu)，填入后主語應該是avoiding procedural confusion，謂語動詞是are。很明顯，avoiding procedural confusion后應跟單數(shù)謂語動詞。所以D也錯，只有B才可能是正確答案。代入句中，符合句意�，�

例題7(1997年8月考題)Because it was so closely related to communication, _____ art form to develop.

(A) drawing was probably the earliest
(B) to draw early was probably
(C) early drawing probably
(D) the earliest draw.

首先，我們分析句子結(jié)構(gòu)。空格前是because引導的原因狀語從句，也就是說，_____art form to develop應該是完整的主謂結(jié)構(gòu)。而單數(shù)的art暗示它應該是修飾名詞form，不定式to develop做補語。所以，空格內(nèi)應填入完整的主謂結(jié)構(gòu)。

這時，我們可以排除選項C和D，剩下選項A和B。仔細對比選項A和B，我們發(fā)現(xiàn)選項A更符合句意，因為drawing這個名詞(畫)才可能是一種藝術(shù)形式(art form)，而動作to draw不可能是一種藝術(shù)形式。所以，正確答案是A。