unexpectedly
To be unprepared means to be unprepared. It comes from the sixth chapter of Yang Yuru's Xinhai Revolution: the Qing army was caught off guard and retreated.
Idiom explanation
It means that things come suddenly and make people unprepared.
The origin of Idioms
Source: the sixth chapter of Yang Yuru's Xinhai Revolution is "the two bridges of Qing army's retreat.".
Analysis of Idioms
Caught off guard
unexpectedly
Cages are a kind of nourishment - juàn láo yǎng wù
old acquaintances and new customers received alike by the shopmen - shēng zhāng shú wèi
ruin the state and destroy the race - wáng guó miè zhǒng