Sentence:  At the same time he watched carefully to see how one attached pegboards to stone walls , but Mr. Blatz was usually standing in his line of vision and it all seemed so simple that he did n't like to <WSD>disclose</WSD> his ignorance . 
Meaning of the word marked with <WSD> tags:  make known to the public information that was previously known only to a few people or that was meant to be kept a secret