Astronomers believe that there are about 100,000 comets that travel through our solar system. Comets are chunks of ice, dust, and gas that
orbit around our Sun. Which of the following can be observed from Earth
as comets get closer to the Sun? *
They explode
Their gases burn
Their tails get longer,
They begin to slow down ,

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

Guard cells control which event? the growth of plants capture of solar energy gas exchange in leaves water absorption in roots

In one or two well-crafted paragraphs in your laboratory journal, summarize the process in which normal cells become cancer cells. your paragraph(s) must include each of the terms listed below. underline each term in your writing: