fall back on是什么意思？

fall back on的音标：fall back on的英式发音音标为：[fɔ:l bæk ɔn]fall back on的美式发音音标为：[fɔl bæk ɑn]...

You can always fall back on him when you are in difficulties.你碰到困难时总是可以求助于他.Doctors sometimes fall back on old cures.有时医生们求助于老的疗法.When necessary, instinct is the most reliable resource you can fall back on.必要时，最保险的办法就是凭直...