杂草中危害通常仅限于叶脉间的条状区域.On grasses, injury is usually confined to areas between the veins.叶脉有两种:平行脉和网状脉.There are two kinds of venation , parallel and net.叶脉中木质部比重越大,越有利于水分的传输.Large proportion of xylem benefit to the water tr...
The news of victory rejoiced the heart of the whole nation.胜利的喜悦使全国人民欢欣鼓舞.When the good news reached there, the whole county rejoiced.喜讯传到那里时, 全县的人都欢欣鼓舞起来.They rejoiced over their own emancipation.他们为自己的解放感到欢欣鼓舞....
复''.'消'.''''.'色差'. ''的矫正色相差和球面像差的, 如镜头.Corrected for both chromatic and spherical aberration, as a lens.当这两种系统消球差、彗差及复消色差后会产生不同的色球差.There is a different spheroc...