2 sentences for 边际 (biān​jì)

1. 他为人詹詹，说话总是不着边际。

   tā wéi​rén zhān zhān, shuō​huà zǒng​shì bù zháo biān​jì.

   He is quite verbose, and his speech is always rambling and off the mark.

   Source: Dong Chinese Dictionary

2. 边际效用递减是经济学的一个基本规律。

   biān​jì xiào​yòng dì​jiǎn shì jīng​jì​xué de yī gè jī​běn guī​lǜ.

   Diminishing marginal utility is a fundamental law of economics.

   Source: Dong Chinese Dictionary