单选题 By dint of much practice, he became ______ and was able to sign his name with either hand.

【正确答案】 D

【答案解析】(ambidextrous双手灵活的)。句意为：通过大量的练习，他的双手都很灵活，能用双手签名。A．practical实际的；B．tricky奸诈的；C．ambiguous模棱两可的。