21.  A dynamometer is used to measure muscle power.

22.  A fan is used to retrieve the flue gas heat, utilising a stainless steel condensing coil.

23.  A fathom is the unit of measurement used in calculating sea depth.

24.  A federal law enforcement official said prosecutions seldom are initiated unless the eavesdropper deliberately has used a monitored conversation for other purposes.

25.  A few dishonest dealers give the used car trade a bad name.

26.  A few motorcycle shops occasionally sell used ones.

27.  A flat stone was used as a table.

28.  A floral chintz fabric is used at the windows and for the upholstered seat and valance under the white bed linen.

29.  A flower bed could be used, or a low wall built.