单选题 Vegetable planting has a respectable tradition. In April 1649, locals responded to high prices and food shortages by cultivating vegetables on common land in Southern England. The practice of throwing seed bombs to turn vacant plots of land green took off in 1970s New York, and has been revived by green-thumbed social media influencers who defy local US regulations in a war on ugly spots in cities.运用略读技巧,根据所提供的文本材料,以下哪项最能概括所给段落的主要内容?( )