问题补充:
单选题Generallyspeaking,thepublisherswillsendyouaspecimencopyoftheirnewbookswhen________.A.requestedB.requestingC.having requestedD.to be requested
答案:
A解析本题考查的是“when + 过去分词”作状语。when requested是when it is requested的省略形式。句意为:通常说来,如果需要,出版商会把他们的新书给你寄个样本来。