### Chinese: 美国海军舰队中14艘“雷鸣潜艇”的行踪通常是被严格保密的。
### English: The whereabouts of the 14 Thunder Submarines in the U.S. Navy's fleet are usually kept strictly confidential.
### Errors: There is a major error at "Thunder Sub". There is a minor error at "'".

### Improved English: The whereabouts of the 14 “Boomer Submarines” in the US Navy fleet are usually strictly confidential.