衛(wèi)生類：基礎(chǔ)語法回顧and

　　7.and 連接兩個名詞做主語時，謂語原則上用復(fù)數(shù)，但是兩個名詞若構(gòu)成一個整體事物時，謂語則用單數(shù)。如：The teacher and his son are picking apples now.(老師和他的兒子在摘蘋果) / Fish and chips is very famous food. (魚和薯條是一種出名的食品)

　　8. there be 句型中be的單復(fù)數(shù)一般由靠近的名詞決定。如：There is a table and four chairs in the room.(房間里有一張桌子和四張椅子)

　　9.用both…and…連接兩個事物做主語時，謂語一般用復(fù)數(shù)。如：Both you and I are required to be here tomorrow.(你和我明天要求都來)

　　10.主語中含有with的短語時，謂語單復(fù)數(shù)由with之前的人物決定。如：A woman with a 7-year-old child was standing at the side of the road. (一名婦女帶著一個七歲的孩子(當(dāng)時)就站在路邊)

　　11.either…or…或者 neither…nor…連接兩個人物做句子主語時，謂語采用就近原則。如：Either you or he is right.(要么是你對，要么是他對。/你和他有一個人是對的) / Neither you nor I am going there.(你和我都不打算去那里)

　　12.表示一段時間或長度概念的復(fù)數(shù)名詞做主語時，謂語一般用單數(shù)。如：Two months is not a short time.(兩個月不是個短時間)Two thousand kilometers is quite a long distance(距離).(兩千千米是相當(dāng)長的一段距離)

　　13.主語中含有half of… / (three quarters)of… / all (of) the ….等詞語時，謂語的單復(fù)數(shù)由名詞確定，如：Over three quarters of the information on the Internet is in English.(因特網(wǎng)上四分之三以上的信息是用英語寫的) / A third of the students were playing near the lake.(學(xué)生的三分之一(當(dāng)時)正在湖邊玩耍) / All of the water in these rivers has been polluted.(這些河流中的水已經(jīng)被污染了)(被動句)

　　但是，population一詞又有特殊情況： What’s the population of China?(中國人口是多少？)(句子用單數(shù)) / Three quarters of the population in this city are Arabs(阿拉伯人).(這個城市四分之三的人口是阿拉伯人)(句子用復(fù)數(shù))