George is lifting weights. He starts by doing biceps curls
which involves flexing his
elbows. His elbow is able to bend
because the humero-ulnar joint is a hinge
joint. Sam is doing leg presses, extending his knees as he pushes
against the weights. Meanwhile, Jane is doing "lat pulls" by pulling
downward on a weighted bar. This movement involves adduction of her arms.
Her shoulder joint is a ball-and-socket joint, allowing
a wide range of movements.
Answer:
colds are cause by viruses
When a predator goes extinct, all of its prey are released from that predation pressure, and they may have big impacts on ecosystems.” ... “If there are too many deer, for example, they can really change the ecosystem because they can destroy forests, and they also carry disease,” Baldwin said.
