Answer:
b.
They can convert the sun's energy into food.
It is a cycle because if your mum or dad was poor then you would be poor unless you were able to get a job too make enough money to be in middle or 1st class
The method is called the displacement method.
You place some water in the graduated cylinder and measure its volume.
Then you add your object and measure the new volume.
The difference between the two volumes is the volume of your object.