Plants are called producers because they make their own food. So the grass is the producer.
the first answer as blood needs to be oxygenated to be passes round the body then when its deoxgenated it will return to the heart to be pumped around the body again
i think it is 3a because when they are all together they are in like a clump so
Natural selection it has to be 20 characters so disreguard the rest
