Complex sentence: In October 1969 Crick participated in a celebration of the 100th year of the journal "Nature" in which he attempted to make some predictions about what the next 30 years would hold for molecular biology.
Split into simpler sentences: In October 1969, Crick participated in a celebration of the 100th year of the journal "Nature". Crick attempted to make some predictions about what the next 30 years would hold for molecular biology.