Aresearcher finds that white bread contains more preservatives and has a higher moisture content than wheat bread. she designs a test to determine whether the type of bread, white or wheat, affects the amount of mold growth. what must be done for the researcher to accurately measure the dependent variable?

a. she will need to allow mold to grow for more days on the white bread, since it contains more preservatives, to measure the dependent variable.
b. she will need to limit the dependent variable to white bread or wheat bread.
c. she will need to allow mold to grow for fewer days on the white bread, since it contains more preservatives, to measure the dependent variable.
d. she will need to learn out how to quantitatively measure mold growth to measure the dependent variable.

(i put 99 points on this; and you'll receive brainliest).

What do butterflies have on their feet which allows them to sense different strengths and types of nectar? a.mechanoreceptors b.acoustic receptors c.substratum receptors d.chemoreceptors

Comedians like to joke that the reason we haven’t been visited by intelligent life from elsewhere in the universe is that aliens have been monitoring earth’s broadcasts of intellectually embarrassing tv programs, like gilligan’s island, fear factor, the jersey shore, and the jerry springer showand so consider us far too primitive to merit a visit. let’s check the assertion that aliens could have been receiving them. tv programs are broadcast at a frequency of about 100mhz with about 100kw of total power in 30frames per second, which emanatesroughly uniformly in all directions. assume that interstellar space transmits these broadcasts without attenuation. no matter how smart they are, aliens would require at least one photon per frame to interpret our signals. findthe number of photons per unit time per unit area reaching a receiver on a possible planet in the nearest star system, which is about 4 light-years away (a light-year is the distance light travels in a year). if aliens aimed a receiver or detector directly at earth, how big (in diameter) would it have to be to receive a photon per frame

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.