I hope that the little（）I’ve been able to do has been of some use.

A. I love history when I was at school.
B. Call me when you’ve finished it.
C. Can you spare five minutes when it is convenient
D. How can they expect to learn anything when they never listen

A. A typhoon causes great damage to crops in this area very often.
B. A typhoon very often causes great damages to crops in this area.
C. A typhoon causes very often great damage to crops in this area.
D. A typhoon causes great damage to crops very often in this area.