24. But coping with salt is not the only challenge for plants in a salt marsh. Soil there is dense and very low in oxygen. So spartinas have air tubes.

但是，适应海碱地带过量的盐分并不足以保障他们的生存，因为那儿的泥土非常紧密，而且含氧量极低，所以，大米草还得长出氧气管。