Nowhere in nature is aluminum found free,owing to its always __ with other elements,most commonly with oxygen.a.combinedb.being combined选哪个,为什么

Nowhere in nature is aluminum found free,owing to its always __ with other elements,most commonly with oxygen.a.combinedb.being combined选哪个,为什么 Aluminum remained unknown until the nineteenth century,because nowhere in nature is it found free,owing to its always being combined withother elements,most commonly with oxygen,for which it has a strong affinity.most commonly with oxygen 这句话 一道英语四级题目Nowhere in nature is aluminum found free,owing to its always ____ with other elements,most commonly with oxygen.A.being combined B.having combined C.to combine D.combined there is a nature park in the There is song nature in the heart nature is above nature in nature everywhere is nowhere without there is a peaceful of nature in the air.nature's beauty touches every heart. Is there a lake in the nature park?该否定 there is a forest in the nature park的意思 is there a nature park in his city?回答句子 what is oliver going to do in the nature nowhere in nature is aluminum found free ,owing to its always ___with otherelements ,most commonly with oxygen A combined B having combiend C combine D being comebined 为什么选D 铝不是应该是主动跟其他物质结合的吗,因该是C啊 in the middle of nowhere nowhere is business better than in Latin America中business是什么词 there is nowhere to A ：live in B：live 选哪个? Nowhere is this more obvious than in science and engineering.此句求细讲解~