把关 [- ɡuān]①(把守关口) guard a pass ②(根据已定的标准， 严格检查， 防止差错) check on strictly; examine carefully to see if sth. is done according to the fixed standard; make the final check:
•¶ 层层把关 make checks at all levels
•¶ 把好质量关 guarantee [ensure] the quality of products