11.   I had the file on my desk a minute ago, but I seem to have lost track of it.

12.   I just lost all track of time.

13.   I lost track of the rest.

14.   I must have lost track of time and my destination, because when I got to the house, it was seven-thirty.

15.   I saw several tracks of rabbit, grouse, and one weasel.

16.   Keep an eye open on muddy paths or patches of snow for the tracks of hedgehogs.

17.   Other designers were also on the track of trailing edge resonance.

18.   Patterns made in fields by the tracks of heavy machinery also frequently resemble patterns associated with archaeological remains.

19.   Police are on the track of a gang that has robbed five mini-Marts in the last month.

20.   Police are on the track of the bank robbers.