In which situation has the independent variable for the experiment been changed?
Check all that apply.
I changed from counting the number of duckweed at day 0 and day 14 to counting them every day
I changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor
tanks
changed from testing the effect of pH on duckweed growth to testing the effect of light levels on
duckweed growth
changed from testing the effect of acid pH on duckweed growth to testing the effect of basic pH on
duckweed growth