----- I hear Tom got caught cheating in the final exam.

----- Yes. Little ________ that we were watching his every move.

A．realised he

B．he did realise

C．he realised

D．did he realise

一种在混凝土搅拌之前或拌制过程中加入的、用以改善新拌混凝土和（或）硬化混凝土性能的材料，称之为（）

A.增强材料

B.减水剂

C.早强剂

D.外加剂