what are they going to talk about this evening ? 强调what,改为强调句怎么改

What is it that they are going to talk about this evening 方法是什么先要知道强调句的结构：
It is + 强调部分+ that-从句
是问句的话，注意倒装那was he abesent from school (because his mother was ill) 括号里强调怎么改Why was it that he was abesent from school ?哦，谢谢了大神