Question:
Which employer did David Blackwell work for in Apr, 1941?

Context:
 David Blackwell works for University of California, Berkeley from Jan, 1954 to Jan, 1989. 
 David Blackwell works for Institute for Advanced Study from Jan, 1941 to Jan, 1942. 
 David Blackwell works for Howard University from Jan, 1944 to Jan, 1954. 
 David Blackwell works for Southern University from Jan, 1942 to Jan, 1943.

Answer:
Question:
Which employer did David Blackwell work for in Apr, 1941?

Context:
 David Blackwell works for University of California, Berkeley from Jan, 1954 to Jan, 1989. 
 David Blackwell works for Institute for Advanced Study from Jan, 1941 to Jan, 1942. 
 David Blackwell works for Howard University from Jan, 1944 to Jan, 1954. 
 David Blackwell works for Southern University from Jan, 1942 to Jan, 1943.

Answer:
user
Institute for Advanced Study
assistant
Question:
Which employer did David Blackwell work for in Apr, 1941?

Context:
 David Blackwell works for University of California, Berkeley from Jan, 1954 to Jan, 1989. 
 David Blackwell works for Institute for Advanced Study from Jan, 1941 to Jan, 1942. 
 David Blackwell works for Howard University from Jan, 1944 to Jan, 1954. 
 David Blackwell works for Southern University from Jan, 1942 to Jan, 1943.

Answer:
user
University of California, Berkeley
Southern University
Howard University
assistant
Question:
Which employer did David Blackwell work for in Apr, 1941?

Context:
 David Blackwell works for University of California, Berkeley from Jan, 1954 to Jan, 1989. 
 David Blackwell works for Institute for Advanced Study from Jan, 1941 to Jan, 1942. 
 David Blackwell works for Howard University from Jan, 1944 to Jan, 1954. 
 David Blackwell works for Southern University from Jan, 1942 to Jan, 1943.

Answer:
user
Institute for Advanced Study
assistant