If you have extracted advice behavior to another class, you can substitute a mock object for your helper object and verify that the advice triggers at the right join points.
Weather the income tax influence on saving behavior is positive or negative depends on the net effect of income effect and substitute effect resulted by the tax saving.
所得税对储蓄行为的影响是积极的还是消极的，取决于税收储蓄的收入效应与替代效应的相对大小。
3
It shows that the synthetic fiber medium, possessing small compressibility and stable resistance behavior, is a good substitute for the board media.