单选题   She worked hard at her task before she felt sure that the results would ______ her long effort.
 
【正确答案】 A
【答案解析】所填词的宾语是her long effort，分析句意，此处意思应该是“结果证明长期努力是正确的”，故答案为A．justify，表示“证明某人或某事有理或正确”。B．testify(证实，表明)；C．identify(识别，鉴定)；D．acidify(使……酸化)。