检测员将 1 mL 水样稀释 10 倍后,用抽样检测的方法检测每毫升蓝藻的数量;将盖玻片放在计数室上,用吸管吸取少许培养液使其自行渗入计数室,并用滤纸吸去多余液体。已知每个计数室由 25×16 = 400 个小格组成,容纳液体的总体积为 0 . 1 mm 3 . 现观察到图中该计数室所示 a 、 b 、 c 、 d 、 e 5 个中格内(每个中格内含 16 个小格)共有蓝藻 n 个,则上述水样中约有蓝藻多少个/ mL ( )
【单选题】During the Second World War about 30,000 Jewish people were given the safe asylum in Shanghai by Chinese people and escaped the atrocities of the Holocaust in Europe. One of them is Ho Fengshan who re...
【简答题】While the number of
mandatory days of vacation in Western Europe is about 30 days, most large U.S.
companies typically offerA. 5 days. B. 10 days. C. 20 days. D. 40 days.