3. Tom cannot cook because he feels very tired today => If __
4. Fuho was so timid in love, so he lost her
=> If __
5. He got fired because he was too lazy.
=> If __

According to Webster Dictionary, Homeostasis is a relatively stable state of equilibrium or a tendency toward such a state between the different but interdependent elements or groups of elements of an organism, population, or group. In simpler words, homeostasis is a period in time where things are relatively balanced and able to adapt to change without causing a lot of problems. I found a few examples involving the human body including body temperature, glucose levels and fluid volume. If you need an extra explanation, I will link the site if examples down below. (: Happy studying! http://www.brighthub.com/science/medical/articles/112024.aspx