名词addition常见有两个意思。它可以指“加，加法”。比如：The child can do addition.这孩子会做加法。She's ready to learn simple addition and subtraction.她准备学习简单的加法和减法。

addition指“附加物”。比如：There are the additions made to the body of the book.这些是本书的增补部分。It was completely refurbished in 1987, with the addition of a picnic site.它于1987年被完全翻修，增添了一个野餐场所。

短语in addition和in addition to都表示两个事物或动作之间的增补关系。在考试中，尤其是完形填空中常见两个由addition构成的短语及搭配。

1.in addition “另外，此外，加之”。一般放在句子的开头，用逗号与句子的后面部分隔开，有时也放在句子中间。比如：

In addition, they held hard work in high regard.此外，他们非常重视努力工作。In addition, during the festival, people make and eat Zongzi.此外，在节日期间，人们包粽子，吃粽子。

You need time and money.In addition, you need hard work.你需要钱和时间，此外你还需要努力。In addition, a nationwide "Clear Your Plate" action has been launched online.另外，一个全国性的“光盘”行动已经在网上启动。

There is, in addition, one further point to make.此外，还有一点要说。You will, in addition, pay to the bank any losses, costs, expenses or legal fees. 另外，你还必须向银行支付所有损失、成本、花销或律师费。

2.in addition to 表示“除……之外(还) ”，它多放在句子的开头，其后面要跟名词或者动名词。比如：

In addition to apples you asked for, he bought you some oranges.除你要的苹果外,他还给你买了些桔子。Of course, in addition to my weekly pay, I got a lot of tips.当然，除了周薪外，我还得到很多小费。

In addition to being a bagger, he's worked at a fast-food restaurant.除了装袋的工作外，他还在一家速食店打工。In addition to these arrangements, extra ambulances will be on duty until midnight.除了这些安排以外，另增救护车值班至午夜。

In addition to theics, the new e-books will include a host of Rough Guide titles.除了经典著作，新的电子图书将包括大量出版社的图书品种。