21. He is determined and competent and intelligent as well, which is ________ it takes to become ______success.
A. that; /         B. what; a         C. what; /          D. that; a 
22. — Mum, I really think Dad should have a break and get relaxed.
   — Yes. He __________ too long.
A. read           B. has been reading     C. had read          D. is reading