题型:问答题 如图是我们所熟悉的一些物质之间的相互转化关系(其中部分生成物及反应条件已略去),A、C、E、F为气体,其中A、F为单质;B、D为液体;反应④、⑤的同一生成物为X.(1)写出有关物质的化学式:A______、D______.(2)在反应①~⑤中,属于置换反应的是______(填序号).(3)写出有关反应的化学方程式:反应②______;X转化为F______.(4)物质B中一定含有的元素是______. 查看答案
题型:问答题 Soon, more of the information we receive via the Internet could come (71) in digital wrappers.Wrappers are made up (72) software code that’s targeted to do specific things with the data (73) within them, such as helping to define queries for search engines. They also keep (74) from (75) access to that code.(75)处填()。A.gainB.gainedC.gainsD.gaining 查看答案