And while concentrated heat on top of city buildings can help tomatoes ripen, it also means more frequent watering, even if irrigation requires lugging watering cans up stairs.

而集中供热的城市建筑物顶部可以帮助西红柿成熟，这也意味着更频繁地浇水，即使浇水灌溉需要你扛着水罐上楼。

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Heat two cans of tomato sauce in a saucepan.

用深平底锅加热两罐番茄酱。

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Next,place the cans again in water and heat the water to one hundred degrees Celsius.

VOA: special.2010.07.19