威爾斯美語忠孝分校

Comparisons - Similarity

as clean as a whistle: Something as clean as a whistle is extremely clean.
This can also mean that a person's criminal record is clean.

as easy as pie: Something that is (as) easy as pie is very easy to do.

as mad as a hatter: To say that someone is as mad as a hatter means that they are very strange or insane.

as hard as nails: A person who is (as) hard as nails is unsentimental and shows no sympathy.