单选题 The man had a good disguise, but as soon as he spoke he______himself.
【正确答案】 C
【答案解析】解析：四个选项的意思分别是：expose暴露，显露；reveal显示，泄露；betray泄漏，暴露；disclosed说出，表明。句意是，这个人善于伪装，但只要他说话便暴露本质。所以正确答案是C选项。