MY MOTHER USED TO ………….…….. RESEARCH IN THIS LIBRARY WHEN SHE WAS...
26. My mother used to ………….…….. research in this library when she was a student.
A. make
B. do
C. doing
D. making
26. My mother used to ………….…….. research in this library when she was a student.
A. make
B. do
C. doing
D. making