Sentence:  <WSD>Assuming</WSD> the weather is halfway decent that day , hundreds of thousands of persons will mass along this thoroughfare as President John F. Kennedy and retiring President Dwight D. Eisenhower leave Capitol Hill following the oath-taking ceremonies and ride down this historic ceremonial route . 
Meaning of the word marked with <WSD> tags:  take to be the case or to be true; accept without verification or proof