Therearetwokindsofchanges—chemicalchangeandphysicalchan...
问题详情：Therearetwokindsofchanges—chemicalchangeandphysicalchange.Inachemicalchange,thereisalwaysanewsubstance(物质)formed.Breakingupwaterintohydrogen(*气)andoxygen(氧气)isachemicalchange.Ineachofthe...