2 sentences

1. 这项任务极具挑战性，但他还是圆满完成了。

   zhè xiàng rèn​wu jí jù tiǎo​zhàn​xìng, dàn tā hái​shi yuán​mǎn wán​chéng le.

   The task was highly challenging, but he completed it successfully.

   Source: Dong Chinese Dictionary

2. 他在那部电影中扮演了一个非常有挑战性的角色。

   tā zài nà bù diàn​yǐng zhōng bàn​yǎn le yī gè fēi​cháng yǒu tiǎo​zhàn​xìng de jué​sè.

   He played a very challenging role in that movie.

   Source: Dong Chinese Dictionary