有必要让公众在充分知情的状况下展开辩论。There needs to be a properly informed public debate.20世纪最了不起的辩论家非列昂·托洛茨基莫属。The greatest polemicist of the 20th century must be Leon Trotsky.他们在方法和观念上都持不同意见，这使辩论精彩了很多。To add spice to the debate, they d...
心皮是由大孢子叶两边愈合进化而来的.It has evolved by fusion of the two edges of the megasporophyll.孢子异型:指植物产生两种大小不同的孢子: 小孢子和大孢子.Heterospory The production of two different sizes of spore: microspores and megaspores.通常较大的大孢子含有更多的贮藏养料.The ...