A:根据化合价Fe3O4可表示为FeO·Fe2O3,则Pb3O4也可表示为PbO·Pb2O3
B:CaC2能水解:CaC2+2H2O= Ca(OH)2 +C2H2↑,则Al4C3也能水解:Al4C3+12H2O =4A1(OH)3 +3CH4↑
C:O2与Cu加热生成CuO,则S与Cu加热生成CuS
D:SO2通入BaCl2溶液不产生沉淀,则SO2通入Ba(NO3)2溶液也不产生沉淀
杨氏之子待客很热情,从____可以看出来;他反应很敏捷,从____可以看出来;她说话委婉而有礼貌,从____可以看出来。
A
It's a beautiful day in summer. There are many people on the beach. Mrs Guo and her two sons are on the beach, too. Look! Mrs Guo is swimming in the sea. She can swim fast. What are her sons doing? They are playing volleyball on the beach. There's a man under the umbrella. He's reading a book. Look! A little girl is collecting shells on the beach. She's very happy.
— It's purple.
如图是动植物细胞结构图,下列关于动植物细胞的叙述,其中不正确的是( )