Which of the following is the best metaphor for an atom

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

Which component of the earth’s atmosphere is decreased due to photosynthesis?

Carmen is load furniture and boxes onto a moving truck. she picks up boxes of her things, places them on a cart, and pushes the cart to the moving van. which term best describes the type of force carmen uses? a. contact b. friction c. gravity d. noncontact