I really wonder he has posted me many parcels we worked together .
A. how ; after
B. why ; when
C. when ; before
D. why ; since
网友回答
A. how ; after
B. why ; when
C. when ; before
(答案→)D. why ; since
解析：英语中的连词since有这样的特性：终止其后从句中的延续性的谓语动词的动作。第二个空白处填入since之后，这个从句的意思是：自从我们不在一起工作起。此外，since还可使其后从句里的非延续性的谓语动词延续。例如：It is 15 years since he joined the Army . (他参军已经十五年了。)