Most people felt __________ regrettable that Yaoming retired from the NBA.
A. one B. this C. it D. what
This old computer must have been of great use to _______ did the scientific research.
| A．those | B．when | C．whoever | D．whomever |
--- Do you know _____ Mr. Black’s address is.
--- He may live at No. 18 or No. 19 of Bridge Street. I'm not sure of _____.
| A．what; which | B．where; which | C．where ; what | D．what; where |
--- Do you know him?
--- Yes, but I can’t remember ________I met him for the first time.
A. where B. what C that D. if
They have not made any decision on ______ they are going to do to deal with the waste and control pollution.
| A．that | B．which | C．if | D．what |
Sometimes we are asked ______ we think the likely result of an action will be.
| A．that | B．what | C．which | D．whether |