The difference is that electromagnetic waves can travel through the vacuum of space but however mechanical waves only travel through air and solid materials
Answer:
Explanation:
The biological or chemical change in the quality of water due to the presence of contaminants in water is called water pollution. Most of this contamination as on date is due to various human activities. In fact, humans are responsible for the mass deaths of whales and other aquatic organisms often swept ashore at different beaches in the world. There is an urgent need to look into the measures to control water pollution although a lot many efforts and schemes have already been announced by the Government in this regard. To make the students aware of this we have prepared short and long essays for students which shall inform them about water pollution and the means to minimise it.
Answer:
1. Height
2. Girth
Explanation:
The woody plants grow in two manners: the primary growth and secondary growth.
The primary growth is considered the type of growth which increases the height of the plant which involves the apical meristem present at the tip of the shoot.
When the height increases up to its maximum length, then secondary growth begins which add tissues to the side that is it increases the girth by adding bark, secondary xylem and phloem.
Thus, Height and Girth is correct.
Answer:
Pia mater
Explanation:
Three meninges cover the brain and spinal cord. Pia mater refers to the deepest meninx of the brain. It is a thin delicate layer of connective tissue. It is a transparent connective tissue layer like that of cellophane. Being a transparent and thin tissue layer, it looks like a cellophane wrap adhered to the surface of the brain.
