1. It will help us to define the dimensions of the cube. (future simp active) 2. For more than four centuries telescopes have been the Earth`s window on the universe. (pres perf active) 3. The telescope is (pres simp active) housed in a tower with a revolving 1000-ton dome. 4. A great many scientists from various institutes were involved to work at the design of the hydro engineering complex. (past simp passive) 5. A special group worked at the system of television control. (past simp active) 6. Physics is one of the ancient sciences about nature.
(pres simp active)