Sentence:  The Illinois Commission for Handicapped Children , which for 20 years has had the responsibility of coordinating the services of tax supported and voluntary organizations <WSD>serving</WSD> handicapped children , of studying the needs of handicapped children in Illinois , and of promoting more adequate services for them , indeed welcomes this new important resource which will help the people of Illinois toward the goal of providing an education for all of its children . 
Meaning of the word marked with <WSD> tags:  be used by; as of a utility