Subject + 保持 + 固定 + 的 + Noun
固定 (gùdìng) means "fixed," "set," or "unchanging," describing something that remains in a stable position or state. It can function as a verb or adjective, as in 固定的形状 (a fixed shape) or 把它固定住 (fix it in place).
每周开会的时间是固定的。
měi zhōu kāihuì de shíjiān shì gùdìng de.
The time for the weekly meeting is fixed.
用胶水把这个零件固定在墙上。
yòng jiāoshuǐ bǎ zhège língjiàn gùdìng zài qiáng shàng.
Use glue to fix this part to the wall.
他没有固定的工作,靠打零工生活。
tā méiyǒu gùdìng de gōngzuò, kào dǎ línggōng shēnghuó.
He doesn't have a steady job and lives by doing odd jobs.