What was the Friday June 3 practice time of the rider who did 20' 50.45 108.623mph on Thursday, June 2?
create table table_29218221_3 (fri_3_june varchar, thurs_2_june varchar, PRIMARY KEY (fri_3_june))
select fri_3_june from table_29218221_3 where thurs_2_june = "20' 50.45 108.623mph"