16) Elizabeth Blackwell，the first woman medical doctor in the United States， founded ［A］ the New York Infirmary， an institution ［B］ that have always had ［C］ a completely female medical staff ［D］ .
17) Each lichen(地衣) consists ［A］ of an alga and a fungus that lives ［B］ together in a kind ［C］ of plant ［D］ partnership.
3. 名词复数＋介词短语
定语从句
＋of＋单数名词[JB)｝] 由于主语是复数名词，其谓语动词要用复数形式
18) The novels of John Cheever belongs ［A］ to a literary ［B］ tradition that is concerned ［C］ primarily ［D］ with manners.
19) Many people who ［A］ live in New York City thinks ［B］ that life ［C］ in a large city offers ［D］ special advantages.
20) Flower ［A］ have long been cultivated ［B］ and bred for their beauty ［C］ and their fragrance ［D］ .
三、对等连词前后的一致
由and, or, but, than, both…and, either…or, rather than 等对等连接词连接起来的成分彼此间在形式上应力求保持一致。具体有以下几个方面
1. 数的平行：对等连词接连起的名词在单复数形式上通常一致，and和both…and连接两个单数名词，谓语动词用复数形式，either…or连接两个单数名词，谓语动词用单数形式
21) Dictionaries may be used to answer question ［A］ , to solve ［B］ problems, or to obtain ［C］ information ［D］ .
22) Both the male and the female working in the field.
［A］ be
［B］ are
［C］ is
［D］ bieng
2. 时态的平行： 在同一时间背景下，对等连词所连接的动词应采用一致的时态
23) A line segment, which is part of a straight line, begins at one point at another.
［A］ ending
［B］ by ending
［C］ the end is
［D］ and ends
24) Gravity not only causes bodies to fall their speed.
［A］ and to increase
［C］ and increases
［B］ but also increase
［D］ but also increases
25) Nearly all trees have seeds that fall to the earth, take root, and eventually .