There was_____rain last year.

A. a lot

B. a lot of

C. quite a few

D. a lots of

B

句意：去年雨水很多。A. a lot副词短语，很多，修饰动词、副词或形容词；B. a lot of形容词短语，很多，修饰可数与不可数名词都可以；C. quite a few 形容词组，修饰名词复数；D. a lots of短语形式错误。rain不可数名词，雨，所以使用形容词组a lot of修饰。 故选：B。