A:用pH试纸测双氧水的pH
B:用酸式滴定管量取20.00 mL酸性K2Cr2O7溶液
C:用托盘天平称取 5.85 g NaCl晶体
D:用带磨口玻璃塞的试剂瓶保存Na2CO3溶液
向20℃的饱和澄清石灰水(甲溶液)中投入适量的氧化钙粉末,充分反应,下列说法错误的是( )
完成句子(10分)
根据所给提示,完成句子。每空一词,含缩略词。(1)He did his homework last night. (改为否定句)He ____ ____ his homework last night.(2)The kid is playing the piano at the school music club. (对划线部分提问)____ is the kid ____ the piano?(3)Visitors love this city because it has historical sights and delicious food. (改为同义句)Visitors love this city ____ ____ its historical sights and delicious food.(4)他两个月没有收到他儿子的信了。(完成译句)He hasn’t ____ ____ his son for two months.