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You need to be more careful when you cycle down a hill than when you cycle up the hill. Why.
What will happen on a see-saw if one boy is big and the other is small. How would the small boy
balance the weight of the big boy?

Study the diagram of a desert food chain . what would most likely happen if the kangaroo rats were killed off and removed from the food chain ?

The diagram shows the layers of earth. convection currents in which region influence the movement of tectonic plates

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food