– Do you know William failed the exam, Jenny?

   -- _____? As far as I know, he is always working hard.

   A. So what             B. How come             C. Why not              D. What for

As far as I know, he is seldom, ______, absent from school.

A．if any             B．if so              C．if ever            D．if not

---Tom has been fired by his boss．
---              ? As far as I know, he is a hardworking and considerate fellow．

— Tom was late for work this afternoon.

— _____？As far as I know, he is fairly punctual.

A.Why not         B. So what        C. How come  D. How about

—Jack is doing nothing at all but study Chinese.