Why is cellular respiration and photosynthesis difficult to understand?

Which of the following is a period in the paleozoic era? devonian cambrian permian all of the above

Need the diagram below, which is not drawn to scale, shows the position of the earth, moon, and sun. what type of eclipse occurs when the earth, moon, and sun are lined up in the order shown? a. planetary eclipse b. solar eclipse c. martian eclipse d. lunar eclipse

Which of the characteristics of life does a virus display