Milkweed, tobacco, and poison ivy plants have adapted what type of measures to protect themselves?
a) behavioral
b) chemical
c) physical
d) territorial

Which units ate used to measure both velocity and speed? check all that apply

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.