His first attempt to line up his defensive barrier looked a rushed job, even to the untrained eye.

Like any professional group, doctors can put up a defensive barrier if told by outsiders that they may be doing something wrong.

With only a few fordable places along the river's course, this presented an ideal natural defensive barrier.

His shown techniques are, which creates a defensive barrier.

Nothing decisive was achieved, but a series of castles were constructed as a marchland defensive barrier.