Because they are coming from the ground and always safe
The correct answer would be the third option. There would be two atoms that can form hydrogen bonds with the water molecules from the molecule NH2CH2CH2OH. The atoms O and N could make hydrogen bonds with H. Hydrogen bond is an intermolecular force that is a dipole-dipole interaction between a hydrogen and an atom of O, F and N.
1. Relative dating
2. I don't know
3. Absolute dating
4. Absolute dating
I hope this helps...
The included angle, i.e. If two pairs of sides of two triangles are in proportion, and the included angles are equal, then the triangles are similar.