Nicolaus steno set down two geologic principles. what are they

Nicolaus Steno set down two geologic principles, they are:
1. Principle of original horizontality: it states that layers of sediments are originally deposited horizontally under the force of gravity.
2. Principle of lateral continuity: it states that layers of sediments initially extend laterally in all directions. 
These two principles are important in the analysis of folded and tilted strata.

It feels feed the echo system

The basic building blocks of dna and rna are nucleotides