29. He hurried to the booking office only__________that all the tickets had been sold out.
| A．to tell | B．to be told | C．told | D．telling |
____he will go to work in a mountain village surprises all of us.
| A．What | B．That | C．Whether | D．If |
_____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 |