Often used for strong defenses, protected systems, or positions that seem impossible to defeat. It commonly appears after verbs like 'feel', 'look', and 'seem', and often takes 'to' when the danger is named.
常見錯誤
The server is invulnerable against hackers.
The server is invulnerable to hackers.
this adjective normally takes 'to' when you name the threat.
This glass cup is invulnerable, so it will not break.
The steel case is almost invulnerable to damage.
invulnerable is a very strong word and sounds wrong for an ordinary fragile object.