Carbon dioxide ___ from burning fuels is the most common of the so-called greenhouse gases.
| A．producing | B．having been produced |
| C．to be produced | D．produced |
. If the water hadn’t been drained out of the mine, no miners _______ alive now.
| A．will be | B．would have been | C．would be | D．have been |
What the young man can’ t _______ is that his mum always treats him like a baby.
| A．support | B．undertake | C．hold | D．bear |
_______ the news, so far, has been good, there may be bad days ahead.
| A．When | B．While | C．If | D．As |
Not until the train pulled into the next station ________ her suitcase gone.
| A．Mary had found | B．had Mary found |
| C．Mary found | D．did Mary find |
He hurried to the booking office only ______ that all the tickets had been sold out.
| A．told | B．to tell | C．to be told | D．telling |