Have a time：有一段时间例句：

1、For example, most data warehouses have a time dimension, but this almost always must be created independently.例如，大多数数据仓库都有时间维度，但是这几乎总是需要单独创建。

have a hard time：好容易；受罪；难过；遭罪;2、The change will be so rapid that many species, including humans, will have a hard time adapting.由于气候变化来得太快，包括人类在内的许多生物，都将很难适应。have a specific time ：有具体的时间3、Does your company have a specific time frame 您的公司是否有具体的时间限制？