Which force requires contact A. the force exerted by air as an object moves through it
B. the force produced by interactions between magnetic objects
C. the force produced by interactions between electrically charged objects
D. the force of attraction between two masses

Chinese privet is a plant that is native to china. over 150 years ago, chinese privet was introduced to the united states as a fast-growing shrub that serves as an excellent privacy hedge. with no natural herbivore, chinese privet quickly established itself and spread in natural areas throughout the southeast and eastern seaboard of the united states. its dominance in these areas has jeopardized the survival of native plant species. chinese privet provides evidence that introducing non-native organisms can cause environmental damage integrated pest management strategies will not decrease chinese privet populations american gardeners can easily control the spread of chinese privet non-native plant species have type i survivorship curves

Kelly ran electricity though a sample of water using electrolysis. the water changed into two gases, x and y. it was not possible to break down the gases x and y into simpler particles.

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they