During my time as a student at ABC University,

Hi,

Question:
I use "when I studied at ABC University" too frequently.
Could you please suggest some clauses to replace it ?

Sentence:
When I studied at ABC University, I was selected to mark exam papers.
When I studied at ABC University, I used SPSS to complete some assignments.


There are some possible clauses.
During my time as a student at ABC University,
During the time as a student at ABC University,
During my student time at ABC University,
When I was a student at ABC University,

Thanks