What action must happen in order for electrons to be transferred between two materials?

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day 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

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Science and technology are interdependent. advances in one lead to advances in the other. give an example of this phenomenon.