单选题 Much has been written on the virtues of natural childbirth, but little research has been done to ______ these virtues.
【正确答案】 A
【答案解析】[解析] 考查动词辨析。本题意为“很多文章写了关于自然分娩的好处，然而相关研究很少”。confirm“证实”，符合句意。B．consult“咨询”；C．confess‘承认”；D．convey“传达”。