"可开闭的吊桥" can be translated into English as "a drawbridge that can be opened and closed" or more concisely as "an operable drawbridge".
"Drawbridge" specifically refers to a type of bridge that can be raised or lowered, often used in castles or for crossing moats.
"Operable" emphasizes that the drawbridge has the functionality of being opened and closed.
Both translations convey the meaning accurately, with the second one being more succinct.