Doyouknowwhydifferen的精選

問題詳情：根據短文內容及首字母提示，填寫所缺單詞，使短文意思完整。每空一詞Doyouknowwhydifferentanimalsorpests(害蟲)havetheir(1)s________colours?Coloursinthemseemtobemainlyusedtoprotectthemselves.Somebirdsli...