1.a (形容词) variety of +N作主语时，谓语动词单复数一般取决于N的数，也就是遵循概念一致的原则：（但是也有例外）
A great variety of books were recently published.
最近出版了各式各样的书。
There is a considerable variety of opinion.有各种各样的看法。
There is a wide variety of patterns to choose from.
有种类繁多的图案可供选择。《牛津高阶英汉双解词典》（这个句子就是个特例）
There is a bewildering variety of software available.
各种可供挑选的软件使人目不暇接。《牛津高阶英汉双解词典》
2.在表达一般意义上的泛指“种种，许多”a (形容词) variety of，这个用不定冠词，经常考试的：
He's a versatile actor who has played a wide variety of parts.
他是个多才多艺的演员，扮演过各种各样的角色。
The forest's dense growth provides nesting places for a wide variety of birds.
森林里茂密的植物为各种各样的鸟儿提供了筑巢的地方。
The test is used to diagnose a variety of diseases.
此项化验可用于诊断多种疾病。
The wetlands are home to a large variety of wildlife.
湿地是多种野生动物的栖息地。
We stock a wide variety of styles and sizes.
我们有各种款式各种尺码的货品。
We offer a whole variety of weekend breaks.
我们提供的周末假日活动丰富多彩，一应俱全。
There is a bewildering variety of software available.
各种可供挑选的软件使人目不暇接。
The club provides a wide variety of activities including tennis, swimming and squash.
这家俱乐部的活动丰富多彩，诸如网球、游泳、壁球等。
He resigned for a variety of reasons.
他由于种种原因辞职了。
People change their mind for a variety of reasons.
人们会由于种种原因改变主意。
A wide variety of hot and cold snacks will be available.
会有各种冷热小吃。
Detailed study of folk music from a variety of countries reveals many close parallels.
仔细研究各国民间音乐后发现了许多非常相似之处。
A variety of heavy industries grew up alongside the port.
各种重工业沿着港口逐渐发展起来。
We're moving forward on a variety of fronts.
我们正在多个方面向前推进。
This small country has an amazing variety of landforms.
这个小国家拥有令人惊叹的丰富的地貌类型。
You will find a wide variety of choices available in school cafeterias.
在学校的自助餐厅里你会发现有很多饮食可供选择。
The island offers such a wide variety of scenery and wildlife.
这个岛屿拥有丰富多样的景致及种类繁多的野生动植物。
Minerals can be absorbed and utilized by the body in a variety of different forms.
人体可通过很多不同形式吸收和利用矿物质。
3. the variety特指各种，种种，许多
I was impressed by the variety of dishes on offer.
所供应的菜肴之丰盛让我心动。
My eyes popped at the sight of the rich variety of food on show.
看到展示的花样繁多的食品，我的眼睛都瞪圆了。
The scientists will study the variety of trees and observe which are fruiting.
科学家将研究各种树木，并观察哪些会结果实。
In China Grace Thompson observed the great variety of loads that were carried by 'slim, erect but muscular Amazons'.
在中国，格雷丝·汤普森看见“苗条、挺直而强健的女人们”携带着各种物品。