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  3. Andrena Gravida is the name of a wild bee declining in the United Kingdom and the Netherlands. A (31) of months ago the recent d

Andrena Gravida is the name of a wild bee declining in the United Kingdom and the Netherlands. A (31) of months ago the recent d

admin2009-06-24  49
问题     Andrena Gravida is the name of a wild bee declining in the United Kingdom and the Netherlands. A (31) of months ago the recent drop in migratory bird populations was known, based on a study (32) in the Netherlands. Now there’s more troubling news from that part of the world: a study released today by the journal Science reports that there’s been a dramatic loss of (33) among wild bees over the past 25 years in Holland.
    There’s (34) to a 70% decline in the variety and (35) of bee (36) in some areas in Britain. A loss of biodiversity is more subtle (37) an overall drop in absolute numbers of (38) or plants, but it’s still (39) a problem because the (40) species in an ecosystem, the more the system (41) on each one of them, and if disease or some other (42) wipes out a species, its function could go unfilled. In the (43) of bees, that (44) is to pollinate plants, both wild and crop plants. And (45) the authors of the study show, there’s been a (46) decline in plants that were once pollinated (47) the disappearing bees. Indeed, it isn’t clear (48) came first, the plant decline or the decline in bees. It’s also not clear (49) any crops are in trouble, only that there’s a potential for it if this trend continues. It’s also not clear (50) it’s happening. Climatic changes caused by global warming are a possibility, but so is the destruction of wild habitat in both countries, as population and industry both expand.

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