Sentence:  Paradoxically , the same week in which Senator McClellan was <WSD>attempting</WSD> to extend the anti-trust act to labor in transportation , the Civil Aeronautics Board was assuring the airlines that if they met in concert to eliminate many costly features of air travel , the action would not be deemed a violation of the anti-trust act . 
Meaning of the word marked with <WSD> tags:  make an effort or attempt