Mary discovered that the cell membrane of a bacteria acts like a fence because it keeps some things in and other things out.

a. observation
b. analogy
c. inference

mary walked into her room where her little son was playing, found a broken window, and thought immediately that her son had broken it.

a. observation
b. analogy
c. inference

mary noticed that her counter top was warm to the touch.

a. observation
b. analogy
c. inference

mary noticed that the side walk was wet and thought that it may have been that the sprinklers had been on recently.

a. observation
b. analogy
c. inference

mary counted and recorded 20 heart beats in 10 seconds.

a. observation
b. analogy
c. inference

the lecturer compared the human eye to a camera lens.

a. observation
b. analogy
c. inference