If a light wave’s wavelength increases by a factor of four (4), its frequency

The authors use the word “backbone” in lines 3 and 39 to indicate that

Which best describes standard precautions?

Which statements about the two fossil images are correct? 1. cave bears are ancestors of plateosaurus. 2. plateosaurus were present on earth before ostracoderms. 3. ostracoderms were the first to die. 4. plateosaurus died after the ostracoderms. 5. cave bears are the oldest fossils.