Renaldo says that concrete is useful because it is a low-maintenance material. Cynthia says that using concrete can be bad because it creates heat islands. Who is right? -Only Cynthia is right.
-Neither is right.
-Both are right.
-Only Renaldo is right.
HELP PLEASE

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

An atom with 7 protons, 6 neutrons, and 7 electrons has an atomic mass of amu. (enter a whole number.) numerical answers expected! answer for blank 1:

Alice did an experiment to find the relationship between the angle at which a ray of light strikes a mirror and the angle at which the mirror reflects the light. she placed a ray box in front of a mirror. she changed the angle at which the light from the ray box struck the mirror and noted the corresponding angle at which the mirror reflected the light. which of the following is the dependent variable in this experiment? the mirror used to reflect the light the ray box used as the source of light angle at which the light from the ray box strikes the mirror angle at which the mirror reflects the light from the ray box