资料题：What does the author mean by saying"they know better now"（　）。

If Europeans thought a drought was something that happened only in Africa, they know better now.After four years of below.normal rainfall (in some case only 10 percent of the annual average) , vast areas of France, Spain, Portugal, Belgium, Britain and Ireland are dry and barren.Water is so low in the canals of northern:France that waterway traffic is forbidden except onweekends.Oyster growers in Brittany report a 30 percent drop in production because of the loss of fresh water in local rivers necessary for oyster breeding.In southeastern England, the rolling green hills of Kent have turned so brown that officials have been weighing plans to pipe in waterfrom Wales.In Portugal, farmers in the southern Alentejo region have held prayer meeting for rain- so far, in vain.Governments in drought-plagued countries are taking drastic measures.Authorities in hard-hit areas of France have banned washing cans and watering lawns.In Britain, water will soon be metered, like gas and electricity."The English have always taken water for granted"says Graham Warren, a spokesman of Britain's National Rivers Authority.''Now they're putting a price on it."Even a sudden end to the drought would not end the misery in some areas.It will take several years of unusually heavy winter main, the experts say, just to bring existing water reservesup to their normal levels.