如图甲所示是小贺同学制作的土豆电池,将电池两极接在电压表的正负接线柱上时,表盘指针偏转情况如图乙所示,则金属片(填“A”或“B”)为电池的负极,该电池提供的电压为伏。要给用四节干电池供电的手电筒提供电量,则需要个这样的土豆电池串联。 答案:【1】B【2】0.4【3】15The fire spread through the hotel very
quickly but everyone ________ get out.
A.had to B.would
C.could D.was
able to