What makes plant material more difficult to digest?

The phlogiston theory in the 17th century attempted to explain burning. the theory stated that combustable objects contained a material called phlogiston, a substance without mass, color, odor, etc. after objects burned, the objects were dephlogistonated and were then in their true form. the phlogiston theory was accepted until the 18th century, when lavoisier proved that combustion requires a gas that has mass. phlogiston is considered a) to be scientific knowledge b) not to be scientific knowledge c) to be proven by scientific method d) to be accepted in the modern scientific community

Which group of algae is characterized by unicellular organisms and includes some members that would be better classified as zooflagellates? euglenophytes red algae sporozoans green algae

Which feature of a human community is similar to a niche in a biological community