—Oh, you have made the same mistake again.

—________ . How ________ I was!

[　　]

I failed again. If only I ________ careful enough!

[　　]

I ____good marks in the maths exam. If only I____ careful enough.

A. can have got, was　　　　 B. could have got, had been

C must have got, were　　　 D should have got, would be

—Look, young man! Where is your foot?

—Sorry, I ________ careful.

[　　]

I failed again. If only I ________ careful enough!

1. A.
   was
2. B.
   had been
3. C.
   would be
4. D.
   am