题干
_______he was laid off last year ______ how serious the economic crisis was.
A：Not until…he realized
B： It was not until… when he realized
C：It is not until…that did he realize
D：It was not until …that he realized
答案(点此获取答案解析）
B
与NaOH溶液、碘水三者混和后可发生如下反应：
