Direction: Sequence the sentences and enter as a digit string (e.g. "3412").
1. The Central African Republic has approved Bitcoin as an official currency.
2. Experts foresee that this will damage the environment as well as the economy.
3. Others claim that this may make money laundering easy and also use up a lot of electricity.
4. Economists criticised this move as a potential risk to the financial stability of the nation.