The small cones on a tree: will be carried away by the wind
could be male or female
indicate the tree is not mature
are the male cones

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

just finished the test, the answer is d, greg is the least cost-effective because he charges the most for the project