Mil
you want to test the effect of soil acidity on plant growth. which of the
following is an example of a controlled experiment to test this?
o
a. the plant type, soil acidity, amount of light, and amount of water
are all varied and studied in a laboratory,
o
b. soil acidity and height of plants growing in a 10 m2 yard are
measured twice in july and twice in august,
c. the soil acidity of plants in a garden that get light and water from
their surroundings is increased after the plants grow to a height of
100 cm.
o
d. the plant type, amount of light, and amount of water are kept
constant while soil acidity is varied for plants in a greenhouse.