【单选题】We haven't seen each other for 20 years, but I recognized him _____ I saw him. Which of the following is wrong ?
【单选题】This is the man()last night.
【简答题】已知X是中学化学中常见的盐,其溶液呈蓝色。构成化合物F的两种元素的原子均可形成与氖原子相同电子层结构的离子,化合物F具有强氧化性。M是常见的金属单质,固体E为红棕色,是常用的颜料。N的氧化物可作为耐火材料。D与H都为气体,且两者相遇会出现红棕色。各物质的转化关系如图所示(部分 反应产物已略去)。 (1)将M丝插入盛有X溶液的试管中,反应一段时间后的现象是____________________。 ...
【单选题】Although we hadn't met for 20 years, I recognized him ______ I saw him.