ir-,不，非，reversible,可倒转的。

1. South Africa was going through a period of irreversible change.

南非正在经历一场不可逆转的变革。

2. The reforms are irreversible.

改革没有回头路。

3. Technology has had an irreversible impact on society.

技术已对社会产生不可逆转的影响.

4. The decision is irreversible.

这一决定不能取消.

5. She could suffer irreversible brain damage if she is not treated within seven days.

如果她在7天之内没有得到治疗，她的大脑有可能遭受不可逆转的损伤。