A:No problem
B:That's all right
C:That's OK
D:Come o
如图2的四幅图中,属于利用热传递改变物体内能的是( )
编号
①
②
③
溶液
0.01mol/L KHC2O4
0.01mol/L K2C2O4
溶液①与溶液②等体积混合
pH
3.1
8.1
未测定
下列溶液中离子的物质的量浓度关系正确的是( )
Susan is looking ___ the window. She is looking ___ a tree. ( )