A flea and a fly were trapped in a flue, and they tried to flee for their life. The flea said to the fly "Let's flee!" and the fly said to the flea "Let's fly!" Finally both the flea and fly managed to flee through a flaw in the flue.Note:1. flea:跳蚤2. trap:设陷阱；诱捕3. flue:烟筒，通气管4. flee:逃跑5. flaw:裂痕；裂缝
