Explanation:
The ribs are a set of twelve bones which form the protective 'cage' of the thorax. They articulate with the vertebral column posteriorly, and terminate anteriorly as cartilage (known as costal cartilage). As part of the bony thorax, the ribs protect the internal thoracic organs.
Answer:
I think that the answer is c. If not then it is probably d or a.
Many farmers in less densely populated area, such as Amazonia, practice slash and burn agriculture, also known as shifting cultivation or swidden agriculture where an area is cleared and then burned for the vegetative remains to release nutrients back into the soil. Shifting cultivation is a system where a farmer uses a piece of land, only to abandon or alter the initial use a short time later. Advantages of shifting cultivation includes; enhance control of pest and disease, inorganic matter addition which provide nutrient to crop, an effective way of weed control
A star’s life expectancy depends on its mass. Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for about 10 billion years. And if the star is very small, with a mass only a tenth that of the Sun, it can keep fusing hydrogen for up to a trillion years, longer than the current age of the universe.
Answer:
Double fertilization
Explanation:
The phenomenon of double fertilization is unique to flowering plants (i.e., angiosperms). Each pollen grain produces two male gametes (sperm cells), one of which fertilizes the egg to form the zygote, whereas the other sperm fuses with polar nuclei in the female gametophyte in order to form a triploid cell (3n) called endosperm. Subsequently, this endosperm will support embryonic growth by supplying storage nutrients and by serving as a mechanical barrier during seed development and germination.