?請(qǐng)看下面這道題：
Mr Smith has bought a little house in the country, around _________ some green trees. A. which is?B. it is?C. which are?D. them are
【分析】此題【分mso-hansi-font-family: 'Times New Roman'">容易誤選A或B，將A、B中的 which 和 it 誤認(rèn)為是其后句子的主語。其實(shí)，此題的最佳答案為C，around which are some green trees 是一個(gè)由around which are some green t; FONT-FAMILY: 'Times New Roman'">“介詞+which”引出的非限制性定語從句，而在該從句中，主語是 some green trees，around which 是表語，所以句子謂語應(yīng)用are，而不是 is。請(qǐng)看類例：Among these people was a foreigner from Europe. 他們當(dāng)中有一個(gè)來自歐洲的 style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'">Among these peopl老外。(句子主語是 a foreigner，among these people 是表語，所以謂語動(dòng)詞用單數(shù) was)On the top of the tree were some birds. 樹頂上有一些鳥。(句子主語為 some birds，on the top of the tree ，是表語，所以謂語動(dòng)詞用復(fù)數(shù) were) The police found a large box under his bed, in which were some sex books. 警察在他的床底下找到一只大箱子，里面裝的是一些黃色書籍。(in which were some sex books 為非限制性定語從句，在該從句中，in which 是表語，some sex books 是主語，所以謂語動(dòng)詞用復(fù)數(shù)were)