common as an old shoe

例句：

1. 1. This is a common mistake many people make.
   这是许多人常犯的一个错误。
2. 2.The common cold is very contagious.
   普通感冒非常容易传染。
3. 3. Common sense tells us that we should not eat raw meat.
   常识告诉我们，我们不应该吃生肉。