预先检验 meaning in Chinese

precheck

This paper shall be eligible only for the inspection of commodities prior to their export which is therefore called preliminary inspection
此单仅用于申请出口商品的预先检验，称出口的预验。
Preferably have blood tests before vaccinated . only people who have never been exposed to hepatitis b should be vaccination
接受乙型肝炎预防疫苗之前，应该预先检验血液，只有从未被乙型肝炎感染过的人，才需要接受疫苗注射。