Land Usage: Over the last five decades, improved farming techniques and technologies have helped to significantly increase crop yields along with a 12% expansion of farmed land use.
				出自-2013年12月阅读原文
				A further expansion of farming area will adversely impact on the world's natural ecosystems
				出自-2013年12月阅读原文
				Over the past two years, the figures on imports and exports seem not to signal a double-dip recession – a renewed decline in the broad level of economic activity in the United States – but an economic expansion.
				出自-2011年12月阅读原文