A:血管A和D属于静脉
B:从A→C血液中二氧化碳增多,氧气减少
C:从F→D血液中二氧化碳减少,氧气增多
D:图甲中B处的氧气会通过血液循环输送到图乙中E处
能保持水的化学性质的粒子是( )
____÷____=____
Since our research so far has not produced any answers to this problem,we need to adopt a different________to doing it.