单选题Itisknowntousthatittakesyearsof

单选题 It is known to us that it takes years of ________ practice to gain ________ skills of ________ expert.A.不填; the; anB.不填; the; theC.the; the; anD.a; 不填; the

A解析practice为不可数名词，此处泛指“实践”，所以不用冠词．expert可数名词，此处表示“一个专家”．因有定语修释，所以skills前使用定冠词．

和我的回答一样，看来我也对了