Other manufacturers building new facilities have located the filling line close to the lyophilizer and have provided a primary barrier extending from the filling line to the lyophilizer.

还有的生产商建造新的车间时，将灌装线和冻干机摆放的很近，并且在灌装机和冻干机之间安装主要的屏障。

youdao

Significant inequalities based on gender, ethnicity, income, language or disabilities are still a major barrier to achieving universal primary education.

UNESCO: CULTURE

Even today, with Chinese children learning English from primary school onwards, it's a barrier that can be almost completely impenetrable at times.

CNN: 5 top tips for China first-timers