英語(yǔ)聽(tīng)力：自然百科 亞馬遜雨林的生命樹(shù)之果

　　Across the river from Belem Brazil, the largest city in the Amazon Basin, the channels are busy with boat traffic. Here traditional river dwellers make a living by harvesting the black fruit of the thin acai palm tree. In this part of the Amazon, acai has been part of the local diet, even before the arrival of the Portuguese.

　　Virtually unknown until 15 years ago, acai juice suddenly is a global super food, riding high on claims that it fights cholesterol, is an anti-aging elixir and even acts as a natural Viagra. But skyrocketing demand has increased the price of acai where it’s most loved in Belem, the epicenter of the acai trade. According to the Associated Press, the city’s residents consume an estimated 200,000 liters of acai each day, making it more popular here than milk. A few years ago, a liter of acai juice costs 52 cents, today it’s 2 dollars and 60 cents.

　　In an area where monthly income often is less than 200 dollars, that price puts it out of reach from many of the people for whom acai is as much a culture as a beverage.

　　We sell just a little acai and we make good money. We can buy our foods, some clothes, a pair of shoes and so on. Before it was different, we sold acai very cheaply.

　　Even in Brazil acai wasn’t known much beyond Belem until the early 1990s. Because the fruit's juice spoils after about 24 hours, it couldn’t be shipped outside the region. But then acai producers figured out a way to freeze the pulp, allowing it to be sent to Brazil’spopulous South . Since freezing robs acai of much of its subtle flavor, producers bite it with Guarana syrup which help the drink catch on in the rest of the country. Healthenthusiasts can be seen using spoons to attack bowls piled high with dark purple slush--the result when the thick frozen pulp is run through a blender. It’s valued for its combination of vitamins, minerals, antioxidants, amino acids and helpful omega fats.

　　Ben-Hur Borges built a factory here five years ago processing acai berries into juice for export to the US and Europe.

　　Up till now, exports have been practically doubling from one year to the next in exported volume. I don’t believe now that there will be sufficient supply the double those of 11,000 tons again.

　　He now hopes to set up acai plantations to reduce its dependence on river dwellers and fluctuating prices.

　　Meanwhile Belem residents still find ways to obtain the fruit despite rising costs. They buy lower quality juice or sacrifice other fruits. That’s because for many, acai with manioc flour, is all they eat for lunch and often dinner. And many will tell you they just can’t feel full without their daily dose of acai.