A:Really?Thank you.
B:Sorry to hear that.
C:It doesn't matter.
在“用托盘天平称物体”的实验中,下列操作正确的是( )
①AlCl3和氨水 ②Na2CO3与盐酸 ③AlCl3和NaOH溶液 ④Fe与氯气(点燃)