What was the Friday June 3 practice time of the rider who did 20' 50.45 108.623mph on Thursday, June 2?
CREATE TABLE "practice_times_and_leaderboard_600cc" (
  "rank" real,
  "rider" text,
  "mon_30_may" text,
  "tues_31_may" text,
  "wed_1_june" text,
  "thurs_2_june" text,
  "fri_3_june" text
);
SELECT "fri_3_june" FROM "practice_times_and_leaderboard_600cc" WHERE "thurs_2_june"='20'' 50.45 108.623mph';