Today,it is estimated that about 60 per cent of domestic rice consumption in China is comprised of crops generated from Yuan's hybrid strains,and his strains have allowed China's farmers to produce around 200 million tons of rice per year.
1.In 1965,it was the first time that African-Americans in USA_____________ to vote,and a higher percentage of blacks than whites voted in a presidential election_____________ in history in 2012.( ?。?/h2>