and连接两个动词的时态

　　First we need to identify actual and potential problems.

　　首先，我们需要弄清实际的问题和潜在的问题。

　　There are three sizes ─ small, medium and large.

　　有三种尺寸——小号、中号和大号。

　　We're going to Germany for Christmas and New Year.

　　我们要去德国过圣诞和新年。

　　We all try and help one another.

　　我们都尽力互相帮助。

　　The project wasted a considerable amount of time and money.

　　那项工程耗费了相当多的时间和资金。