A:①吸收氨气制氨水
B:②制取少量蒸馏水
C:③转移溶液
D:④除去杂质气体CO2
下列选项中,不属于器官的是( )
There are 50 students in our class. 75% students like going hiking. What does 75% mean? _________.
读某地等高线图(单位:m),回答问题。