For 920 i sourced some information from this site
www.new.wales.gov.uk
For 904 you are looking at why early intervention is important, what steps would your setting take if you noticed a child was falling below his/her developmental mile stones e.g contact health visitor, share concerns with parent/carer, contact the local LEA Special needs co-ordinator who will help put in place a programme of activities or put in neccessary support to help the group the child and the family
I hope that helps remeber you will describe what procedures your setting does or what you would do if faced with this situation