Ros Atkins on... questions for the government over unsafe concrete
More than 150 schools in England have been identified as having a type of potentially dangerous concrete - with many buildings and classrooms closing until they can be made safe.
But how long will that take? And how many more schools could be affected by RAAC (reinforced autoclaved aerated concrete)?
The BBC's Analysis editor, Ros Atkins, looks at the key questions.
