考点一：

　　复数原则：两个或者两个以上的名词由and连接作主语时，或主语由both … and … 连接时，谓语动词一般用复数。

　　如：Both reading and writing are very important. (读写都很重要。)

　　注意：当主语由and连结时，如果它表示一个单一的概念，即指同一人或同一物时，谓语动词用单数，and 此时连接的两个词前只有一个冠词。(考查重点)例如：

　　The iron and steel industry is very important to our life.

　　钢铁工业对我们的生活有重要意义。(钢铁表示同一概念)

　　The playwright and director was present at the party last night.

　　编剧兼导演出席了昨晚的宴会。 (指同一个人)

　　=>试比较： The playwright and the director were present at the party last night.

　　　　　　　编剧和导演都出席了昨晚的宴会(指两个人)