The rebel held and cleg as rebel-held enclave is coming sustain under sustained pressure from the army.

反叛者控制这块飞地受到来自军队持续不断压力。

Imperfective aspect: indicating a present, ongoing, continuous, or recurrent action.The present and the imperfect tense convey this aspect.

我去查了希腊文动词时态，有里面现在持续，(Imperfective aspect) 一个现在开始持续不断动作。