root cause[根本原因] - [拓]direct/primary cause[直接/主要原因];

　　propensity[倾向]

　　- eg: violence propensity[暴力倾向]

　　These juvenile offenders are in need of treatment because they have a negative deposition & high propensity to continue committing crime.

　　怎么样?感觉是不是很简单?只要多加练习，相信大家一定会取得优异的成绩。