11.   The sensor would be able to detect minute traces of plastic explosives that are imperceptible to metal detectors.

12.   The swab was then inserted in a machine that can detect traces of explosives.

13.   They prod the Rice sisters for a family history, trying to detect traces of sibling rivalry and traits they believe will help them tell their waitresses apart.

14.   They had treated the walls of the school, recently repainted by the local Serbs, to detect traces of blood underneath.

15.   While most of the water was fine, in many bottles the tests detected traces of microbial or chemical contamination.

16.   Company experts using magnifying glasses and microscopes detected traces of polish on the coins.

17.   Czechoslovak specialist troops were the only ones who detected traces of nerve gas in the Saudi Arabian desert during the Gulf War.

18.   Israeli radio reports said sniffer dogs belonging to a special police unit detected the traces of explosives.

19.   Israeli radio reports said the woman is a British national, and that sniffer dogs belonging to a special police unit detected the traces of explosives.

20.   It detected traces of toxic compounds in the air and sand on two days during the war, and reported that to Saudi troops.