天气突然变化，气温急剧下降。

Tiānqì tūrán biànhuà, qìwēn jíjù xiàjiàng.

The weather suddenly changed, and the temperature dropped rapidly.

这个行业近年来发展得非常急剧。

Zhège hángyè jìnnián lái fāzhǎn dé fēicháng jíjù.

This industry has developed very rapidly in recent years.

他的健康状况急剧恶化，需要及时治疗。

Tā de jiànkāng zhuàngkuàng jíjù èhuà, xūyào jíshí zhìliáo.

His health condition has deteriorated rapidly and requires timely treatment.