This underground network of fighters, which included Iblis, was safely separated into cells so that no one could betray the others.

Carving took a year and a half, and in September 1831 the column safely separated from the rock.

Finally, at 12:31 p.m., Teperman determined that Risa's right lobe could be safely separated from her left.

Normally safely separated from flowing blood, their contact with blood usually means the blood vessel wall is ruptured and bleeding.

Under these rules, pilots use their eyesight to keep planes safely separated, rather than depending on ground controllers using radarscopes.

Safety groups said the study underscored the need for better runway markings and new radar to keep planes safely separated.

Normally, such planes can be safely separated by two miles.

Here, primary reliance is put on pilots' eyesight rather than on controllers at radar scopes to keep planes safely separated.

This was because the controllers, with no radar to watch, could not then be confident that the straying craft was safely separated from other planes.

Controllers can then radio altitude or speed changes to make sure planes keep properly and safely separated.