a quantity of/quantities of主谓一致问题
主谓一致是高中英语考试的重要考点之一，其中不乏难题，尤其是带有限定词的名词短语作主语时，最难选择谓语的单复数形式。
例如，“a quantity of +名词”作主语时，谓语是用单数还是用复数就让广大考生困惑不已，因为目前的教辅读物中众说纷纭，矛盾重重，让人莫衷一是，到底是用单数还是用复数呢？且看下文：
问题篇：
下述几例选自学生中很有市场的几种教辅读物，他们的结论让学生误入歧途：
1.《高中专项无敌---语法》（新疆青少年出版社---王建村）
（P74）a large quantity of 不管后面跟可数名词还是不可数名词，都要用单数动词，比较：Large quantities of money have been sent there.
A large quantity of books has been offered to us.
2．《各个击破丛书（高中英语专项）---语法》（延边人民出版社---王建军）
（数词与主谓一致p24）
A (large) quantity of 修饰可数或不可数名词，其短语作主语时，谓语动词用单数。
例如：A large quantity of people is needed here.
(large) quantities of修饰可数或不可数名词，其短语作主语时，谓语动词用复数。
例如：Quantities of food (nuts) were on the table.
专家观点：
1.徐广联在《大学英语语法讲座与测试》（华东理工大学出版社）中表示，a quantity of 只能修饰不可数名词，谓语动词用单数。
A quantity of 间或也可以修饰可数名词，例如，A quantity of baskets were on sale.
2.张怀信在《英语高考活用图解辞典》（延边大学出版社）中讲到，a large/small quantity of 大量的/ 少量的（可以修饰可数名词或不可数名词），例如，I need a large quantity of oil (apples). quantities of 大批的，大量的，例如，Large quantities of polluted water are flowing into the sea. 该书所附〈语法祥解篇--- 主谓一致〉还明确指出“在以上（a lot of, lots of, plenty of, a large quantity of + 名词）的词组后面的名词是中心词，谓语动词根据后面的名词的数而定”。
3.顾南华在《中高级英语考试指南》（华中工学院出版社）中说，a quantity of, quantities of 可跟可数名词与不可数名词, 并举有三例：There is a large quantity of milk. Great quantities of fish are caught on the high sea. Large quantities of water are needed for cooling purposes.
在452 页讲到“a quantity of + 不可数名词”，谓语只用单数，“quantities of + 可数与不可数名词”，谓语要用复数。
4.章振邦在《新编英语语法》（上海译文出版社）212 页中讲到，a quantity of 既可用于复数可数名词，也可用于不可数名词。
例如, A large quantity of flowers were heaped on the martyr’s tomb. A large quantity of beer was consumed. Quantities of food were on the table.
5.刘锐诚在《学生使用英语高考必备》（中国青年出版社）中认为，a quantity of + 名词[C,U][+ 单或复数动词] ，quantities of + 名词[C,U] [+ 复数动词] 。
6.张鑫友在《英语语法难题新探（句法篇）》（中国地质大学出版社）529 页中说，在…a large quantity of…等短语后既可接复数可数名词，亦可接不可数名词。
在它们分别和其后的名词构成短语作主语时，其谓语动词通常跟of 后名词的具体情况而采用单数或复数形式。
综上所述，结论就是：
1.a quantity of 后既可接复数可数名词，亦可接不可数名词。
在它们分别和其后的名词构成短语作主语时，其谓语动词通常看of 后名词的具体情况而采用单数或复数形式。
如果是接不可数名词，则谓语用单数形式，如果是接复数可数名词，则谓语通常要采用复数形式（※偶而接单数式谓语，属非规范用法，宜慎用。
）
2.quantities of 后既可接复数可数名词，亦可接不可数名词, 后面的谓语都用复数形式。
举例证明：
1.On January 18, a large quantity of coloured photopaper, dried seafood, canned abalone, audio equipment and antibiotics worth HH$16million were found in four 40-foot containers, bound for…( In brief--- China Daily, HK Edition, 20050122, P2)
2.Besides, a large quantity of mail bags were found. ( US nationals arrested for DVD
piracy---China Daily, 20040731, P1)
3.An undetermined quantity of weapons and ammunition were also seized, the spokesman said. (Raid in karbala and shots fired in Baghdad ---China Daily, 2003102, P1)
4.…and a small quantity of dangerous drugs were seized. (Travel scheme causes concern in HK---China Daily, 20030822, P2)A
5.A quantity of fake certificates and official stamps were also seized. (Police seize 59 in major gang smash, 20030403)
6.“…and a large quantity of drugs is reading different segments。