#四六级写作背诵范文精选(21-30)7 搜索结果
27.ScientificTheoriesInscience,atheoryisareasonableexplanationofobservedeventsthatarerelated.Atheoryofteninvolvesanimaginarymodelthathelpsscientistspicturethewayanobservedeventcouldbeproduced.Agoodexampleo
