Since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. So as the mass of either object increases, the force of gravitational attraction between them also increases. If the mass of one of the objects is doubled, then the force of gravity between them is doubled. If the mass of one of the objects is tripled, then the force of gravity between them is tripled. If the mass of both of the objects is doubled, then the force of gravity between them is quadrupled; and so on.
Hope this helps.
OK so very difficult but I will try,
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The appropriate answer is D. Alfalfa. Alfalfa is a legume and these plants play a key role in the nitrogen cycle. These plants house nitrogen fixing bacteria on their roots. The bacteria are housed in tiny round structures of leguminous plant roots. Once the nitrogen is fixed in the soil it can now be used by other plants to make food. These plants include beans peas and peanuts. <span />
