A、To lock up their garages at night. B、To leave their cars in the garages unlocked. C、To lock up their cars even when they are k

(29) The recent increase in car stealing has alarmed the police, who are looking for what they now believe must be a well-organized gang of professional car thieves.
    Most of the thefts have taken place in the rich residential areas round South-well Park, where last week alone, twenty-two car thefts were reported to the local police. Of course, (30)only one has been found abandoned in Rocking-hill Palace road twenty miles away. The others have not been found yet, except tot one which had been falsely reported missing. The owner later admitted that he had forgotten where he had parked it a few days before.
    An interesting aspect of these thefts is that nearly all the missing vehicles have been taken from locked garages. The owners now admitted that they may have left the car doors unlocked, but only one owner was not certain whether he had locked the garage dour. The police have therefore assumed that the gang find it easier to break into garages, where vehicles are often left unlocked at night, than into locked cars, parked on the road-side in day time or at night. (31)They advise car owner to lock up their cars, even when they are kept in locked garages.