This forms a sludge which must be periodically removed from the system.

But any crumbled rock had been periodically removed from the road surface.

It can be removed and cleaned periodically by the individual or a care giver.

Wood shavings generated during turning will also need to be periodically removed.

Wrong answers are periodically removed from the five choices provided until only two are left.

Here the end products are constantly or periodically removed, resulting in constant production of biogas.

The interrogators periodically remove the rag, and the correspondent is seen to gasp for breath.

His friends periodically removed the bottle and swigged from it, while putting pills into the corpse's mouth.

But to know what has actually been in the air, samples must be removed from the unit periodically and taken to a laboratory for genetic testing.

People haul garbage to a large trailer, which is removed from the island periodically by a rented landing craft.