un-, 不，非，able, 能够的。

1. Many areas in the country'sinterior are unable to report Aids cases immediately.

该国内地的很多地区无法即时报告艾滋病病例。

2. The military government has been unable to win popular support.

军政府一直未能赢得广泛的支持。

3. He had been unable to keep to his schedule.

他没能遵循自己的计划。

4. Oil majors need not fear being unable to sell their crude.

大型石油公司无需担心原油销售不出去。

5. When the children misbehaved she was unable to cope.

孩子们调皮捣蛋的时候她管不了。