<human>:  Why was Singapore a British colony?
<bot>: Singapore was a British colony because the British needed to control the opium trade. In the 1800s, opium was a very popular drug in China. The Chinese government didn't want the British to sell opium, so they taxed it. But the British were selling it anyway, so the Chinese government tried to stop them. The British needed to get rid of the opium, so they made a deal with the Chinese government: they would pay the Chinese government to stop selling opium in exchange for control of the opium trade.