We are paying for the house by ______installments.

We are paying for the house by ______installments.
A、months
B、monthlies
C、month
D、monthly
【正确答案】：D
【题目解析】：频度状语表示事件或状态发生的频率，可被“How often，How many times”提问。可由副词组成（如daily，weekly，monthly，annually，habitually，commonly，invariably，often，frequently，always等），或名词词组（如three times）、介词词组（如from time to time等）或分句（如whenever等）组成。