He is so careless that he is ________ making mistakes in his homework．

A.extraordinarily

B.completely

C.continuously

D.constantly

答案及解析： D

句意为：“他那么粗心，总是在作业中不断的犯错。”extraordinarily“杰出的”；completely“完全地”；continuously“继续地”；constantly “不断，经常地”。