A:硫酸铜溶液与氢氧化钡溶液反应:Ba2++SO42-= BaSO4↓
B:向氯化铝溶液中加入过量氢氧化钠溶液:Al3++4OH—=AlO+2H2O
C:氯化亚铁溶液中通入少量氯气:Cl2+ 2Fe2+=2Fe3+ +2Cl—
D:碳酸钙加入稀盐酸: CaCO3+2H+=Ca2+ +CO2↑+H2O
算一算.
①Mum hello family a thin girl your mother Mr Wang
②Is he a fat teacher? No,he isn't. He's a thin teacher.
北京将在2022年举办冬季奥运会,你认为比赛时间最适宜安排在( )
读一读,选出不同类的单词。
____ A. panda B. tiger C. lion D. zoo
____ A. monkeys B. big C. strong D. old
____ A. they B. my C. our D. its
____ A. cool B. elephant C. hot D. long