Complex sentence: The first race of the season was held at Oulton Park but the race was cancelled because of snow on the track anyway, Siffert drove the 15th time in practice and was almost seven seconds behind the fastest man Jim Clark.
Split into simpler sentences: The first race of the season was scheduled for Oulton Park but although practice was held the race was cancelled because of snow on the track. Siffert was 15th in practice, almost seven seconds behind the fastest man Jim Clark.