答：common “普通的,一般的”侧重常见的常有的,人人皆知的
如：Apples are very common in North China.苹果在华北很常见.
也可指“平凡的等”,如 the common people 平民
normal “正常的,标准的,普通的” 侧重与常规,标准等一致,如
the normal temperature of the human body 人的正常体温
The baby's weight is normal.