第14题: [单项选择]Sulphur has occasionally been found in the earth in an almost pure state. A. regularly B. accidentally C. sometimes D. successfully 参考答案:B 答案解析:本题是对副词的考查。题干划线词occasionally意为“偶尔地”,四个选项中:regularly意为“规律地”,accidentally意为“偶尔地”,sometimes意为“有时”,succes