题目

The Greens ______ in Paris and now they _______ in China. They like China.   A. used to live, are used to living   B. are used to living, used to live   C. use to live, used to live             D. used living, used to living 答案：A17．空气是人类的宝贵资源，下列有关空气的说法错误的是（（　　）A．空气的成分按体积计算，含量最多的气体是氮气B．空气是混合物C．氧气具有可燃性D．稀有气体的化学性质不活泼