2points
to test a new drug that has the potential of curing people of the common
cold, a company asked human volunteers who were coughing and sneezing
to participate in a clinical study. the objective of the experiment was to test
whether the new drug could cure the volunteers in the experimental group of
the common cold. but instead of two groups, these volunteers were randomly
divided into three groups and treated as follows:
group
experimental
group
control
group #1
control
group #2
no
yes
no
new drug
orange juice
bed rest
no
yes
yes
yes
yes
yes
which of the following is the best explanation of why a second control group
was included in this experiment?

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

the potatoes have high sugar concentrations and although these potatoes were different we could seethe effects that their sugar concentrations had in different environments. for example, the potatoes in sample a, were placed in pure water. this created a hypertonic environment and caused the potatoes to draw in water from its surroundings. we saw the opposite happen with the potatoes in sample b when placed in the sodium chloride solution. the potatoes in this case were in a hypotonic solution and therefore lost water to their surroundings.

what are the options? add them, then i will be glad to .