CREATE TABLE table_name_66 (number INTEGER, opponent VARCHAR, time VARCHAR)
SELECT SUM(number) FROM table_name_66 WHERE opponent = "fokker d.vii" AND time = 600
คู่ต่อสู้ Fokker d.vii หมายเลขใดด้วยเวลา 600?
What number has the opponent Fokker d.vii with a time of 600?