<span>the question like this is called assumptions, but the assumptions have to be proved by experiments and prove to be the best, but generally in science, theories might change from time to time, so in science, it is necessary to prove the hypothesis, not just by putting up the theories.
hope this helps </span>
These sentences can be complete in the following way:
1) Nadie.- this would mean that you do not know anyone.
2) Ningún- it makes reference to the book. you do not have a book
3) nunca. This means that you do not do that activity. you never do it
4) ni. not having one thing nor the other.
5) nada. this means that the table is empty- nothing on it.
Las orejas
la boca
el cuello
el hombro
el estomago
las peirnas