向后兼容

向的英语翻译：

always; at; be partial to; direction; face; out; to; toward
【医】 ad-; ak-; ob-

后的英语翻译：

after; back; behind; offspring; queen
【医】 meta-; post-; retro-

兼的英语翻译：

concurrently; double; hold two or more posts concurrently; twice

容的英语翻译：

allow; appearance; contain; hold; looks; tolerate