Question:
Who was the chair of National Cancer Institute in Feb, 2018?

Context:
 Harold E. Varmus is the chair of National Cancer Institute from Jan, 2010 to Jan, 2015. 
 Norman Sharpless is the chair of National Cancer Institute from Oct, 2017 to Dec, 2022. 
 Douglas R. Lowy is the chair of National Cancer Institute from Apr, 2015 to Oct, 2017.

Answer:
Question:
Who was the chair of National Cancer Institute in Feb, 2018?

Context:
 Harold E. Varmus is the chair of National Cancer Institute from Jan, 2010 to Jan, 2015. 
 Norman Sharpless is the chair of National Cancer Institute from Oct, 2017 to Dec, 2022. 
 Douglas R. Lowy is the chair of National Cancer Institute from Apr, 2015 to Oct, 2017.

Answer:
user
Norman Sharpless
assistant
Question:
Who was the chair of National Cancer Institute in Feb, 2018?

Context:
 Harold E. Varmus is the chair of National Cancer Institute from Jan, 2010 to Jan, 2015. 
 Norman Sharpless is the chair of National Cancer Institute from Oct, 2017 to Dec, 2022. 
 Douglas R. Lowy is the chair of National Cancer Institute from Apr, 2015 to Oct, 2017.

Answer:
user
Harold E. Varmus
Douglas R. Lowy
assistant
Question:
Who was the chair of National Cancer Institute in Feb, 2018?

Context:
 Harold E. Varmus is the chair of National Cancer Institute from Jan, 2010 to Jan, 2015. 
 Norman Sharpless is the chair of National Cancer Institute from Oct, 2017 to Dec, 2022. 
 Douglas R. Lowy is the chair of National Cancer Institute from Apr, 2015 to Oct, 2017.

Answer:
user
Norman Sharpless
assistant