A．unemployment is a hot potato for economists to study.
B．unemployment is the topic that interests Mr. Phelps the most.
C．Mr. Phelps’s parents asked him to study unemployment.
D．Mr. Phelps’s research is based on the existing research results.

A．had a great influence on some countries.
B．is no longer as outspoken as it used to be.
C．has decided to embark on an organizational reform.
D．was founded by some major Western countries.