Sentence:  More recently , the chairman of the Atomic Energy Commission , Dr. Glenn T. Seaborg , `` admitted '' to a news conference in Las Vegas , Nevada , that the US might fall behind Russia ( he apparently meant in weapons development ) if the Soviets continue to test in the atmosphere while we <WSD>abstain</WSD> . 
Meaning of the word marked with <WSD> tags:  choose not to consume