抹灰装饰层由底层、中层和面层三个层次组成，各层抹会不宜过厚，其中底层抹灰的厚度为（）

     The measure of a man's real character is what he would do if he knew he would never be found out.
-Thomas Macaulay。
     Some thirty years ago, I was studying in a public school in New York. One day, Mrs Nanette O'Neill
gave an arithmetic__1__to our class. When the papers were__2__,she discovered that twelve boys had
made the same mistakes throughout the test.
     "There is really nothing new about__3__in the exams. Perhaps that was why Mrs O'Neill__4__even
say a word about it. She only asked the twelve boys to__5__after class. I was one of the twelve.
Mrs O'Neill asked__6__questions, and she didn't__7__us either." She wrote on the blackboard the
__8__words by Thomas Macaulay. She then ordered us to__9__these words into our exercisebooks
one hundred times.
     I don't__10__about the other eleven boys. Speaking for myself I can say: it was the most important
single__11__of my life. Thirty years after being introduced to Macaulay's words, they__12__seem to me
the best yardstick(准绳), because they give me a__13__to measure myself rather than others.__14__of us
are asked to make__15__decisions about nations going to war or armies going to battle. But all of us are
called__16__daily to make a great many personal decisions.__17__the wallet, found in the street, be put
into a pocket or turned over to the policeman? Should the__18__change received at the store be forgotten
or__19__? Nobody will know except__20__. But you have to live with yourself, and it is always better to
live with someone you respect。