1.the limits of ...的范围
For this to happen, you must plan truthfully and avoid planning beyond the limits of your understanding.
要做到这点，您必须真实地规划，避免规划超出您能理解的范围。

2.no longer necessary 不再必要
Similarly, it is no longer necessary to kill whales to work out what they have been eating, as this can be determined from DNA in samples of faeces.
同样的，现在也没有必要以杀死鲸鱼的方式来了解鲸鱼的摄食习性，因为这可从鲸鱼的粪便样本里的DNA中得知。