foolproof
5.It is impossible to make anything foolproof because fools are so ingenious.
7.a foolproof identification system; the unfailing sign of an amateur; an unfailing test.
8.While acts of vandalism tend to be corrected quickly, the system is far from foolproof.
9.We must develop a foolproof argument in order to effectively illustrate the urgency of implement stringent environmental protection measures .
10.I finally wrote what I thought would be a foolproof note: Dear Madam: Will you please let this nigger boy -- I used the word "nigger "to make the librarian feel that I could not possibly be the author of the note -- have some books by H.L.Mencken?
