4) underground sources is the best answer.
Oceans have saline not fresh water and morning dew would not be sufficient water.
Answer:
10 because if we talk about the metric system time and meter etc then they are expressed in the powers of 10
A is what the human body treats school as
The secondary structure is responsible for the shape that the nucleic acid assumes. The bases in the DNA are classified as purines and pyrimidines. ... A purine base always pairs with a pyrimidine base (guanine (G) pairs with cytosine (C) and adenine (A) pairs with thymine (T) or uracil (U)).