What tool is use to measure an objects mass? ?

What does it mean if an area has high biodiversity? select one: a. different organisms live in the world b. lots of different organisms live an ecosystem c. lots of the exact same organisms live in an ecosystem

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

What did hunter gathers do to alter the environment?