Question:
Which employer did Donald N. Langenberg work for in Apr, 1988?

Context:
 Donald N. Langenberg works for University of Illinois at Chicago from Jan, 1983 to Jan, 1990. 
 Donald N. Langenberg works for University System of Maryland from Jan, 1990 to Jan, 2002. 
 Donald N. Langenberg works for National Science Foundation from Jan, 1980 to Jan, 1982.

Answer:
Question:
Which employer did Donald N. Langenberg work for in Apr, 1988?

Context:
 Donald N. Langenberg works for University of Illinois at Chicago from Jan, 1983 to Jan, 1990. 
 Donald N. Langenberg works for University System of Maryland from Jan, 1990 to Jan, 2002. 
 Donald N. Langenberg works for National Science Foundation from Jan, 1980 to Jan, 1982.

Answer:
user
University of Illinois at Chicago
assistant
Question:
Which employer did Donald N. Langenberg work for in Apr, 1988?

Context:
 Donald N. Langenberg works for University of Illinois at Chicago from Jan, 1983 to Jan, 1990. 
 Donald N. Langenberg works for University System of Maryland from Jan, 1990 to Jan, 2002. 
 Donald N. Langenberg works for National Science Foundation from Jan, 1980 to Jan, 1982.

Answer:
user
National Science Foundation
University System of Maryland
assistant
Question:
Which employer did Donald N. Langenberg work for in Apr, 1988?

Context:
 Donald N. Langenberg works for University of Illinois at Chicago from Jan, 1983 to Jan, 1990. 
 Donald N. Langenberg works for University System of Maryland from Jan, 1990 to Jan, 2002. 
 Donald N. Langenberg works for National Science Foundation from Jan, 1980 to Jan, 1982.

Answer:
user
University of Illinois at Chicago
assistant