Answer:
is about 4.6 billion years old
Worms don't have lungs. They breathe through their skin.
Hope this helps. :)
Capillaries have thin walls, only one cell thick, that allow them to effectively perform their function.
Answer:
The correct answer is <em>c. animal wastes and fertilizers. </em>
Explanation:
Two major sources of nitrate pollution are farming and breeding activities. There are also certain industrial activities involved in nitrate pollution, but in general, these industries are related to agriculture.
The indiscriminate use of fertilizers for several years in intensive productions produce high nitrate concentration in soil and consequently elevate the risk of nitrate lixiviation.
Breeding animals produce nitrate pollution by their wastes, which accumulate and are not treated. These wastes include flesh, hair, feathers, skin, fat, liquids, excrements, among others. These wastes are an important source of nitrate.
In many cases, animal wastes are used by farmers as organic matter to improve their production. But excessive and incorrect use of it might produce severe damage in water sources.
Answer:
a) protons b) neutrons c) electrons d) +1 e) nucleus f) -1 g) atomic number h) mass number
Explanation:
