--I think your father is very busy.--So he is. he still takes a walk with us sometimes.A.

问题补充：

--I think your father is very busy.

--So he is. he still takes a walk with us sometimes.

A. So

B. And

C. Or

D. But

答案：

A. So

B. And

C. Or

(答案→)D. But

解析：考查连词。So因此，And并且，Or否则，But但是。句意：我认为你的父亲非常忙。他的确很忙，但是有时候他仍然和我们一起散步。根据前后文的内容关系，可知答案为D，表示转折意思。