—There is still a copy of the book in the library. Will you go and borrow ?
—No, I’d rather buy in the bookstore.
| A．it;one | B．one;one | C．one;it | D．it;it |
_____more countries can use natural energy in the future remains to be seen.
| A．Whether | B．This | C．who | D．If |
It worried her a bit _____her hair was turning gray.
| A．while | B．if | C．that | D．for |
.____the meeting should last two days or three days doesn’t matter.
| A．That | B．Whether | C．If | D．Where |
Is _____he said really true?
| A．that | B． what | C．why | D．whether |
The question came up at the meeting_____ we had enough money for our research.
| A．that | B．which | C．whether | D．if |