What does it mean to say that photosynthesis and respiration are gas exchange processes?

Which of the following is not a way in which a vascular plant's xylem and phloem are similar?

What is the name of the two satelites on mars

Need an answer asap 45 points and brainlest to the first person to answer why do scientific theories, such as biological and chemical evolution, represent the strongest explanation of the changes observed in the fossil record. must be in sentence form how can scientific theories on evolution and the fossil record change over time? must be in sentence form