反映人为地向水中加入强氧化剂,迅速氧化有机物,氧化剂消耗量越大,说明水质受污染越严重的指标是
A.溶解氧B.化学耗氧量C.生化需氧量D.结合氧E.总需氧量
参考答案:B
髓部有异常维管束的药材是()
A.何首乌
B.商陆
C.牛膝
D.大黄
E.川牛膝
He telephoned me________he arrived in the city. [ ]
A. immediate
B. first time
C. immediately
D. direct