单选题
Charles Goodyear's discovery of vulcanized rubber began when he inadvertently spilled a mixture of rubber and sulfur on a hot stove.
【正确答案】
D
【答案解析】[词义辨析] inadvertently'“出于无心地”与D项的accidentally“偶然地”意义比较接近。Experimentally“试验地”；unceasingly“不停地”；incompetently“不胜任地”。