這個句子謂語動詞的識別稍有難度。
1. the fact 后描述的部分是這個fact的具體內(nèi)容,所以the fact后為同位語從句;
2. a practice ...to feed on 作同位語。only algae of a size后出現(xiàn)的that could be collected ina net 對前者解釋說明作用,為典型的后者定語從句;
3. 類似的that overlooked the smallerphytoplankton that we now know grazers are most likely to feed on 修飾說明a practice, 即為后者的后者定語從句。其中 that we now know grazersare most likely to feed on 為the smaller phytoplankton 的后者定語從句。仔細分析,we now know 類似插入語,如果在之前加as則更像比較狀語從句。當然這個定語從句也可以寫成 on which we now knowgrazers are most likely to feed;
4. led to 為整句謂語動詞,于是 a de-emphasis 為整句賓語。
整句主干很簡單,即Perhaps the fact let to a de-emphasis.但主語后跟了自帶一個小級別定語從句的后置定語從句,接著又跟了個自帶一個后置定語從句(同樣嵌套了自己的定語從句)的同位語,讀句子過程中,我們的思路容易被這些非主干成分打斷。
例句2
The hydrologic cycle, a major topic inthis science, is the complete cycle of phenomena through which water passes,beginning as atmospheric water vapor, passing into liquid and solid form asprecipitation, thence along and into the ground surface, and finally againreturning to the form of atmospheric water vapor by means of evaporation andtranspiration.
1. 大多數(shù)同學可以準確識別出全句的主系表結(jié)構(gòu);
2. a major topic 顯然做前面hydrologic cycle 的同位語;
3. the complete cycle of phenomena 是一個標準的“A of B”結(jié)構(gòu),我們知道,of B修飾/限定/解釋/說明 A,主詞為A;
4. 看到through which…可知后面是個定語從句;which定語從句里主謂是water passes, 后面跟了beginning, passing和 returning 三組現(xiàn)在分詞伴隨狀語。其中returning 部分稍稍復雜,bymeans of evaporation and transpiration 為這個伴隨狀語內(nèi)部的方式狀語;
5. 需要注意的是處于句首或句尾的伴隨狀語,必須和主語一致。本句中beginning, passing和 returning三個動作的發(fā)起者都是water. 如果不一致,則應(yīng)轉(zhuǎn)化為獨立主格結(jié)構(gòu)。
這個句子描述的水循環(huán)圈如下圖所示。整句主干可簡化為The circle is the circle, 只是表語后跟了較長的后置定語從句稍稍增加了難度。