But there was a constant exchange of messages between the two kings.
There is a constant exchange of energy in the form of heat radiation between the ground and the atmosphere.
But the constant exchange between familiar and new information also operates on a more individual basis.
The gunfire drew closer, but there was never anything like a constant exchange.
"There is a constant exchange of counterterrorism information and fragments," the official said.
Each may tackle different elements of a project, but the crucial conceptual work results from a constant exchange.
There was also the constant exchange of letters, seeds and plants with his overseas correspondents.
During these visits there was a constant exchange of goods and gifts.
There could be losses as well as gains from the constant exchange of men.
A constant exchange is facilitated by the use of English as a common working language.