1.   In theory, the mechanism should also prevent anyone launching the missiles accidentally.

2.   But unlike standard music files, the copies cannot be duplicated, and an internal encryption mechanism prevents them from being played on other computers.

3.   Oliveira said a malfunctioning release mechanism prevented the ordnance from fully releasing.

4.   The subway system relies on two mechanisms to prevent subway collisions, Toronto Councilman Joe Pantalone said.

5.   The subway system relies on two mechanisms to prevent subway collisions, Toronto councillor Joe Pantalone said.