Which did Kepler notice about planetary motion that caused him to propose Kepler's first law of orbital motion? (1 point)

The distance to the sun varies

Most planets have highly elliptical orbits.

The planets have circular orbits.

The distance between Mars and the sun is constant

3points hurry! what is the relationship between biotechnology, sharkskin, and disease resistance? bioengineers have developed an artificial sharkskin that does not allow resistant bacteria to grow on it. disease-causing microbes have been genetically modified to keep them from infecting the skins of sharks. scientists have created a device that can be attached to the skins of sharks that dramatically increases their abilities to resist disease. sharkskin produces many chemicals that can be collected and used to create antibiotics.

Why do we perceive objects as retaining their brightness under different lighting levels?

Eutrophication caused by human nutrient pollution.