foreign body in bladder

例句：

1. 1. The foreign body was causingthe infection.
   这个异物导致了感染。
2. 2. The foreignbody had to be removed surgically.
   这个异物必须通过外科手术移除。
3. 3. The foreignbody was found in the patient'sbloodstream.
   这个异物被发现存在于患者的血液中。