A grey recurrent populationimprovement of wheat was suggested by combining the grey breeding method with the wheat dwarf male-sterile technology.
将灰色育种方法与矮败群体改良方法相结合，提出了小麦灰色轮回群体改良方法。
2
Where salt iodization has been in place for at least a year, improvement in iodine status within the population has been overwhelming.
在食盐碘化已至少进行一年的地方，人群中的碘状况已取得确凿的改善。
3
The slowest improvement has been in the WHO African Region, where the percentage of the population using toilets or latrines increased from 30% in 1990 to 34% in 2008.