关于对几个单词的理解，求解！！

spoonzUID: 3480552

1. pedigree这个单词大家觉得它的意思跟谁跟接近？ breeding or purity
2. herbs跟plants有啥区别吗？herbivorous吃的是plants, 不是herbs?
3. past跟previous是同义词还是反义词啊？有点晕乎
谢谢啦

AZliutingUID: 3581047

先回答第二个问题，以下的解释取自oxford learner's dictionaries

herb:a plant whose leaves, flowers or seeds are used to flavour food, in medicines or for   their pleasant smell. Parsley, mint and oregano are all herbs.

plant：[countable] a living thing that grows in the earth and usually has a stem, leaves and roots, especially one that is smaller than a tree or bush

从解释可以看出plant是包含了herb，herb的范围更小，指可用于食物，调料，医药或香水中的草本植物。

herbivorous：plant-eating（取自Merriam-Webster's vocabulary builder)

AZliutingUID: 3581047

第三个问题：以下的释义均取自oxford learner's dictionaries
（在此两词都是作为形容词来进行对比，后接名词）

previous:1, happening or existing before the event or object that you are talking about.
               2, immediately before the time you are talking about.

例句：The car has only had one previous owner.
        I couldn't believe it when I heard the news. I'd only seen him the previous day.

past：1， gone by in time。
          2，[only before noun] gone by recently; just ended
          3，[only before noun] belonging to an earlier time
例句：I haven't seen much of her in the past few weeks.
         Let's forget about who was more to blame—it's all past history.

我个人的感觉是previous与past相比，previous更多的是与顺序，排列有关，意为前一个，但时间上的概念较弱。past指过去的，时间上的概念较强。还是要根据语境和后接的名词来决定用past还是previous吧            

AZliutingUID: 3581047

pedigree有名词和动词两种形式，楼主是问pedigree作为名词的意思吧。

pedigree：The line of ancestors of a person or animal. 我觉得更接近族谱家谱的意思，即family tree.

pedigree的前缀ped- 是一个拉丁词，意为foot，也就是这个词是与foot有关。因为很多人觉得family tree的形状（即这个图案/|\，一般family tree都是这样画的）与鹤的爪的形状很像（crane's foot），所以这个词与foot有关。pedigree一般是指纯血统动物（purebred animals）的族谱，与purity和breeding还是有区别的。

以上参考自Merriam-Webster's Vocabulary Builder