227. You must do it in case   以防万一，你必须这样做。

W: Everyone should remember their safety education.
每个人都应该记住安全教育的内容。

M: It's not necessary.
没必要。

W: You must do it in case of emergency.
以防万一，你必须这样做。

M: The children should be home early in the evening.
晚上孩子应该早点回家。

W: The social security is not bad now.
现在的社会治安不差。

M: You must do it in case.
以防万一，你必须这样做。