__________ in her office for nearly 20 hours, she is going home to have a rest.
| A．To work |
| B．Working |
| C．To have worked |
| D．Having worked |
We can never expect ________ bluer sky unless we create ________ less polluted world.(2009·安徽)
| A．a；a | B．a；the | C．the；a | D．the；the |
Experts think that ________ recently discovered painting may be ________ Picasso.
| A．the；/ | B．a；the | C．a；/ | D．the；a |
Take your time—it's just ________ short distance from here to ________ restaurant.
| A．/；the | B．a；the | C．the；a | D．/；a |
Carl is studying ________ food science at college and hopes to open up ________ meat processing factory of his own one day.
| A．/；a | B．/；the | C．the；a | D．the；the |
Sarah looked at ________ finished painting with ________ satisfaction.
| A．/；a | B．a；the | C．the；/ | D．the；a |