在与少数民族交往时,入乡随俗是对他们的尊重,也是有礼貌的表现。( )
“黑火药”是我国古代四大发明之一,它由硝酸钾、硫磺、木炭组成,属于( )
In Switzerland, things like glass and plastic _____ into different groups and then recycled