At universities across Britain allotment societies are blossoming, spurred on by students keen to use any available outdoor space to grow their own food. allotment:供出租的小块菜地; spur:刺激 主要是第一句的句式及理解
At universities across Britain 为地点状语,其后如果有个逗号,就更清楚了。 allotment societies 为整个句子的主语 spurred on by students 为该句子的另一个状语 整句的含义为: 受到那些一见户外有空地就开发出来种植粮食的学生的追捧,在英国的很多大学里,自给自足社团正在兴旺起来。