所谓“（）”是指承包商向招标单位提出承包该工程项目的价格和条件，供招标单位选择以获得承包权的活动。

A、投标；

B、标底；

C、招标；

D、评标。

一 Where have you been all day?

— I _____ some former classmates and I couldn't get back until it was dark. [ ]

A. have met

B. met

C. would meet

D. had met