拉开 + Object / 拉开 + 了 + 序幕
拉开 (lākāi) is a verb meaning "to pull open" or "to start." In its literal sense, it means to pull something apart or open, like a curtain or zipper. Figuratively, it means "to kick off" or "to begin," as in 拉开序幕 (to raise the curtain, i.e., to begin an event).
她拉开窗帘,阳光一下子照了进来。
Tā lākāi chuānglián, yángguāng yīxiàzi zhào le jìnlái.
She pulled open the curtains, and sunlight immediately flooded in.
这场音乐会拉开了艺术节的序幕。
Zhè chǎng yīnyuèhuì lākāi le yìshùjié de xùmù.
This concert opened the curtain on the art festival.