The answer is B.
Im pretty sure water is important for some organisms.
According to the second law of thermodynamics, energy is never 100% efficient because some of the energy disperses as heat.
English: Density is MassUnit Volume; relative density is the density compared to a reference substance (usually water) under standard conditions.
Nepali: घनत्व मास एकाई भोल्यूम हो; सापेक्ष घनत्व मानक अवस्था अन्तर्गत सन्दर्भ पदार्थ (सामान्यतया पानी) को तुलनामा घनत्व हो।
The correct answer is they are produced by cyanobacteria.
Stromatolites are being produced by cyanobacteria.
Stromatolites are termed as layered mounds, which have columns and also sheet like rocks which are originally formed with growth of layers.
Lichen stromatolites is a type of stromatolite which is formed by layered structures rocks and they are formed above water.
