active block theory的用法和样例：
- learns active block theory and research method, discusses demarcation method of active block, and intruduces active block demarcation in northeast margin of Qinghai-Tibet detailedly;
- Inside the utensil was cast six characters posy.The curling sheep horn, sheep head, and cow head were all composed by active block patterns.
- The block theory is applied in the key block identification in metal mines to find out the law of the orebody overburden destruction and movement.
- The result of forecasting is consistent with the fact one.The applicability of block theory in overbreak of doubled arch tunnel is tested.