early warningFalling pH is typical of mature tanks and can be an early warning of a decline in water quality.
police are warningBut police are warning members of the public not to approach him.
issue a warningOne year on, many still ask why the authorities did not issue a warning, based on intelligence reports, about a Christmas terrorist threat.
give warningHence, to give warning, we shall find no easy way to combine a natural science approach with an interpretative one.
word of warningA word of warning…
advance warningHowever, if you are given advance warning, think about the stay and about the meals you will have to provide.