So the carbon dioxide comes in through the stomata, makes it's way through gaps in the airy layer of cells (called spongy mesophyll) at the bottom part of the leaf, then heads up to the palisade layer for photosynthesis.

因此，二氧化碳通过气孔进入，通过叶片底部通风层细胞（称为海绵状叶肉）的间隙，然后到达栅栏层进行光合作用。