偶函数的傅里叶级数中不含__________。

A million motorists leave their cars filled up with petrol and with the keys in the ignition every day. The cars aye sitting in petrol stations while drivers pay for their (36) . The Automobile Association (A. A. ) has discovered that cars are left (37) for an average three minutes and sometimes longer as drivers buy drinks, sweets, cigarettes and other (38) items. With payment of credit cards becoming more and more common, it is not unusual for a driver to be out of his car for as long as six minutes. (39) the car thief with a golden opportunity.
For more than ten years there has been a bigger rise in car (40) than in most other types of crime. An (41) of more than two cars a minute are broken into or stolen in the UK. Car crime (42) for almost a third of all reported (43) with no signs that the trend is slowing down.
(44) . Amateur thieves are aided, in most cases, by our own carelessness. The A.A. ply recommends (45) . A partially open sunroof or window is a further come-on to thieves.
There are many other traps to avoid. The A.A. has found little awareness among drivers about safe parking. (46) . The A. A. advises drivers to park in places with people around. Thieves don’t like audiences.