Question

It is known to us that it takes years of ________ practice to gain ________ skills of ________ expert.

1. A.
   不填; the; an
2. B.
   不填; the; the
3. C.
   the; the; an
4. D.
   a; 不填; the

Answer 1

A
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．