ability of self-directed studying的用法和样例：
- Therefore, the strategy is to improve study efficiency and to develope the ability of self fullfillness.
- The self - directed study of a language.
- Knowledge of self increases as one gets older.
- Stem cell is an ideal target cell with the ability of self renewing and multi differentiation, and can proliferate and keep multi differentiation potential when it is suitably cultivated in vitro.
- Mental rotation is both an ability of imagining rotation of self or the object in the field of spatial representation transformation and an important means to evaluate spatial intelligence.