They should__school by eight o'clock.A are B be at C are at D be

They should__school by eight o'clock.A are B be at C are at D be they they they They they books are____(they) They.,did they?(造句) They They need light here they here they Here they they复数 They have they单数 they宾格 what()they()they()there?what()they()they()there?[do] They like They are