EB是下列哪一种化学成分?() ["聚丙烯酰胺","溴化乙锭","溴酚蓝","甲基蓝","载样缓冲液"]
一般绿肥的翻压时期以()翻压较好。 ["出苗前后","穗分化期前后","花期前后","成熟期前后"]
膜增生性肾炎为() ["补体持续降低","补体于6~8周恢复正常","补体降低可提示病变活动","血清补体可降低","血清补体正常"]
氮肥供应过量,会造成作物()。 ["矮小","徒长","叶片发黄","生长缓慢"]
双链形悬挂
已知一个有向图的邻接矩阵表示,删除所有从第i个顶点出发的方法是()。