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 |
When we saw the road ________ with snow, we decided to spend the holiday at home.
| A．block | B．to block |
| C．blocking | D．blocked |
I still remember________to the Famen Temple and what I saw there.
| A．to take | B．to be taken |
| C．taking | D．being taken |
Lydia doesn't feel like______abroad.Her parents are old.
| A．study | B．studying |
| C．studied | D．to study |
I remembered ________ the door before I left the office, but forgot to turn off the lights.
| A．locking | B．to lock |
| C．having locked | D．to have locked |
________ warm at night, I would fill the woodstove, then set my alarm clock for midnight so I could refill it.
| A．Staying | B．Stayed |
| C．To stay | D．Stay |