<unk> <unk> <unk> <unk> <unk>  David Marshall, leader of the Labour Front, became the first Chief Minister of Singapore. ️<unk>️<unk>️<unk>️<unk>️ Social unrest was on the rise, and in May 1955, the Hock Lee bus riots broke out, killing four people and seriously discrediting Marshall's government.<unk> ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️  Question: What year did the Chinese Middle School riot break out?
1956 <unk> <unk>