关井时,应先关()。 ["总闸","油管闸门","针形阀","闸阀"]
种子植物维管形成层属分生组织,其细胞特点是什么?() ["全部为等直径细胞,核大、质浓,无大液泡,能进行各种方向分裂","全部为纺锤形具大液泡,能进行各种方向细胞分裂","部分细胞为纺锤形,具大液泡,能进行各种方向细胞分裂","部分细胞为纺锤形,具大液泡,只能进行平周分裂"]
The declaration made by the shipper,if embodied in the bill of lading,is()evidence,but is not binding or conclusive on the carrier. ["absolute","important","decisive","prima facie"]
指出下列植物器官属于变态茎的是() ①荸荠 ②芋头 ③甘薯 ④马铃薯 ⑤洋葱 ⑥胡萝卜 ⑦水仙 ⑧藕 ["①②⑤⑦","③④⑤⑥","①②④⑧","③④⑦⑧"]
气水混合流动时,由于水的()比气大,引起的额外消耗的能量称为滑脱损失。 ["分子质量","质量","体积","密度"]
建筑装饰内墙涂料分哪几类?