question: What was the Friday June 3 practice time of the rider who did 20' 50.45 108.623mph on Thursday, June 2?
answer: SELECT fri_3_june FROM table_29218221_3 WHERE thurs_2_june = "20' 50.45 108.623mph"
context: CREATE TABLE table_29218221_3 (fri_3_june VARCHAR, thurs_2_june VARCHAR)