此时 + Subject + Verb Phrase
The time word 此时 (cǐshí) means 'at this moment' or 'at that time,' and is used to refer to a specific point in a narrative. It has a somewhat formal or literary tone and is commonly found in written Chinese to set the scene or mark a turning point in a story.
此时天已经黑了,街上没有几个人。
cǐshí tiān yǐjīng hēi le, jiē shàng méiyǒu jǐ gè rén.
By this time it was already dark, and there were hardly any people on the street.
她打开门,此时一阵冷风吹了进来。
tā dǎkāi mén, cǐshí yī zhèn lěngfēng chuī le jìnlái.
She opened the door, and at that moment a gust of cold wind blew in.
此时他才明白,一切都已经来不及了。
cǐshí tā cái míngbái, yīqiè dōu yǐjīng láibùjí le.
Only then did he realize that it was already too late for everything.