Answer:
Twice a year
Explanation:
Your question is incomplete, but I assume that the sentence you were given is:
The women’s club held fundraisers on a semiannual basis.
The underlined word is semiannual. The prefix in this word is semi-, which means half. For example, a semicircle is half a circle.
Semiannual means twice a year. Once half a year passed, the women's club held a fundraiser, meaning that they organized fundraisers twice a year.
