Answer:
Lichens are not parasitic when they grow on trees, they just use the tree bark as a home. They enrich the soil by trapping water, dust and silt. When lichens die they contribute organic matter to the soil, improving the soil so that other plants can grow there.
A) None of the Moon’s face is visible from Earth
Hasan most likely has rickets
Rickets is a disease of children which is caused by vitamin D deficiency. Rickets softens and weakens bones in affected children. Symptoms of rickets include bowed legs, pain in the bones, stunted growth, trouble sleeping and muscle weakness. Rickets can lead to other health problems such as intellectual disability and muscle spasms.
Here is what I found, its quite interesting, I hope it helps..
https://www.fbi.gov/services/laboratory/biometric-analysis/codis/codis-and-ndis-fact-sheet