Answer:
Because a stationary front marks the boundary between two air masses, there are often differences in air temperature and wind on opposite sides of it. The weather is often cloudy along a stationary front, and rain or snow often falls, especially if the front is in an area of low atmospheric pressure.
Answer:
D. The threat of predators to eat eggs
Explanation:
The internal gestation followed by live birth was an adaptation developed by the mammals on land, and by some fish in the water, like the sharks. The mammals have been the most marking ones in this adaptation though. They too were producing eggs initially, but because they were living in an environment where there were numerous animals that preyed upon them, as well as their eggs, they had to be innovative. They developed internal gestation, where the embryo was developing inside the body of the female, and then it was born alive. This was providing extra safety, as the embryo was always with the mother, instead of being left alone and not guarded, thus an easy meal for the predators. The two types of internal gestation that the mammals developed are the placental and marsupial types, with the placental turning out to be more successful over time.
An afterglow may appear above the highest clouds in the hour of fading twilight or be reflected off high snowfields in mountain regions long after sunset. The particles produce a scattering effect upon the component parts of white light. The opposite of an afterglow is a foreglow, which occurs before sunrise.
<span>It
is truth that most of the unicellular organisms like bacteria, are
among the simplest life forms we know about it, but there are many
other unicellular organisms, like amoebas, warnowiids and algae, that
are far more complex. They can even have thousand of nuclei and be
visible with the naked eye. Some amoeba actively hunt their pray, and
some warnowiids even evolved and structure that functions like an eye;
so even though unicellular, they are not simple organisms at all.</span>
