Раскройте скобки, употребив нужную форму причастия

1. The horns of antelopes and the anters of deer are obvious examples of weapons possessed by mammals.2. Almost every cell known to man is microscopic in size, that is cells can't be observed with the unaiding eye.3. The lisosome, discovered in the mid — 1950's, is a spherical, saclike body containing a number of hidrolyc enzymes.4. By the time we got home we all felt exhausted5. The plasma membrane, sometimes referred to as the cell membrane, is located at the surface of the cytoplasmic portion of the cell.