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 energy-rich western province has a testy relationship with the federal government.这是西部一个有着非常丰富资源的省份，它和政府的关系很不稳定。They become lamb cropschops Testy once Tasty ones , says Daivd David Johnson.大卫继续说它们将变成好吃的羊排.Jack Pan: W...