使用以下JSON-LD结构化数据，Google测试工具会引发错误：

{
  "@context": "http://schema.org","@type": "Person","name" : "Brent","makesOffer" : {
        "@type" :"Offer","priceSpecification" : {
            "@type" : "UnitPriceSpecification","priceCurrency" : "USD","price" : "18000" },"itemOffered" : {
            "@type" : "Car","name" : "2009 Volkswagen Golf V GTI MY09 Direct-Shift Gearbox","description" : "2009 Volkswagen Golf V GTI MY09 Direct-Shift Gearbox in perfect mechanical condition and low kilometres. It's impressive 2.0 litre turbo engine makes every drive a fun experience. Well looked after by one owner with full service history. It drives like new and has only done 50,000kms. (...)","image" : "2009_Volkswagen_Golf_V_GTI_MY09.png","color" : "Black","numberOfForwardGears" : "6","vehicleEngine" : {
            "@type": "Enginespecification","name" : "4 cylinder Petrol Turbo Intercooled 2.0 L (1984 cc)"
            },"numberOfAirbags" : "6"
        }
    }
}

抛出的错误是：您必须指出要约，评论或AggregateRating。

但是这些数据是schema.org在其汽车标记页面上提供的通用示例。

那么，为什么在使用schema.org建议的方法时Google会弹出错误消息？

为澄清起见，数据如下：

Person 
-> makesOffer
--> itemOffered 
---> car

无论您何时走那条路（一个提供某些东西的人），似乎Google都会抛出错误