Comparing “jūrán” and “jìngrán”

他明明知道这件事有多严重，最后居然还是没有及时告诉大家。

Tā míngmíng zhīdào zhè jiàn shì yǒu duō yánzhòng, zuìhòu jūrán háishi méiyǒu jíshí gàosu dàjiā.

He clearly knew how serious this matter was, yet unexpectedly he still did not tell everyone in time.

经过这么多年的努力，这个原本不被看好的项目竟然真的成功了。

Jīngguò zhème duō nián de nǔlì, zhège yuánběn bù bèi kànhǎo de xiàngmù jìngrán zhēn de chénggōng le.

After so many years of effort, this originally unpromising project unexpectedly really succeeded.

她看了半天，居然没认出站在自己面前的人是多年未见的老朋友。

Tā kàn le bàntiān, jūrán méi rèn chū zhàn zài zìjǐ miànqián de rén shì duō nián wèi jiàn de lǎo péngyou.

She looked for a long time and unexpectedly failed to recognize that the person standing in front of her was an old friend she had not seen for many years.

那样一个看似普通的细节，后来竟然成为判断整个事件性质的关键。

Nàyàng yí ge kàn sì pǔtōng de xìjié, hòulái jìngrán chéngwéi pànduàn zhěng ge shìjiàn xìngzhì de guānjiàn.

Such an ordinary-looking detail unexpectedly later became the key to judging the nature of the entire event.