很多生物体中雄配子与雌配子是不同的.In many organisms the male and female gametes are different.雄配子不能与雌配子结合.The male gamete could not unite with the female.花粉是种子植物的雄配子体, 在有性繁殖中发挥著重要作用.Pollen is the male - gamete of seed plant, which plays...
The interior flatlands and valleys are thickly planted with coconuts.内陆的平地和山谷中种着茂密的椰子树。Buildings old and new are thickly covered with graffiti.新老建筑上都有密密麻麻的涂鸦。That part of Castle Walk is not thickly vegetated.卡斯尔步行街那一地段的植...
Through the separation, lignosulfonate with narrow molecular weight distribution was obtained and then chemically modified.木质素磺酸盐是一种常见的普通减水剂, 其分子量分布较宽,从而影响减水剂性能.The graft mechanism of lignosulfonate and acrylic acid was ...