补充

in time和on time
in time及时
on time准时
The bus arrived on time so I got up in time.公车准时到达,我及时上了车.

principle & principal
The principal's principle is not to leave any child behind.校长的信条是不让任何一个孩子掉队.

accept & except
We accept all major credit cards except Discover.我们收除了Discover以外的所有信用卡.

personal & personnel
The personnel's person information is confidencial.员工的私人信息是保密的.