So it's a good idea is to begin at the bottom, with the least important systems, and work your way up.

Apart from the family, it was the most important educational system of the people.

The "red tape" cut by the administration is actually an important system of controls that helps prevent American weapons from getting into the wrong hands.

This room is obviously the key element in an important system of controls.

On the space station, some of the 760XD's will be used not just to gather data, but also to control important systems.

Vision is an important sensory system for most species of fish.

Islamic scholars consider this important in running a smooth family system.

In addition, advances in technology are making operating systems less important.

Some of the important systems were little better than these, and operated only marginally-when they worked at all.

Congress and the courts, working together, have done a remarkable job creating a substantial, important judicial system.