下列各项操作中,发生“先产生沉淀,然后沉淀又完全溶解”现象的是( ) A . 向硫酸铝溶液中逐滴加入过量氨水 B . 向硫酸铝溶液中逐滴加入过量氢氧化钡溶液 C . 向硅酸钠溶液中逐滴加入过量稀盐酸 D . 向氢氧化钡溶液中缓缓通入过量二氧化碳 答案:DTom
was ________ to win the 100-metre hurdles, but he fell to the ground and missed
the chance..
A. possible B. probable C.
likely D.
maybe