Mr. Howard,_________his study of the situation, was ready to tal

Mr. Howard,_________his study of the situation, was ready to talk about it when I arrived.
A、completed
B、having completed
C、had completed
D、being completed
【正确答案】：B
【题目解析】：分析句子成份可知后半句中已经有谓语动词了。一个句子中只能有一个谓语动词，所以可排除选项A和C；主语是Mr. Harwad，与complete之间是主动关系，无需用被动语态，故选B。