Consider an elliptic system in diagonal form of which the nonlinear terms are of quadratical growth respect to the gradient of the unknownsolution.
考虑一类对角型椭圆组，它的非线性项关于未知解的梯度为二次增长。
2
When the tipping point comes, and all of the unknown reagent has reacted, the solution changes colour.
当滴定终点到来时，所有的未知溶液全都完成了化学反应，溶液的颜色就会发生变化。
3
A good solution is to consider what the worst case scenario of failing would be, because once you do that, it's never as bad as when the scenario was an unknown.