码头上有很多工人在装卸货物。

Mǎtóu shàng yǒu hěn duō gōngrén zài zhuāngxiè huòwù.

There are many workers loading and unloading goods at the dock.

装卸集装箱时一定要注意安全。

Zhuāngxiè jízhuāngxiāng shí yídìng yào zhùyì ānquán.

You must pay attention to safety when loading and unloading containers.

为了提高效率，他们引进了自动装卸系统。

Wèile tígāo xiàolǜ, tāmen yǐnjìn le zìdòng zhuāngxiè xìtǒng.

To improve efficiency, they introduced an automatic loading and unloading system.