The scientist’s many years’ careful observation ____ a surprising discovery.
| A．ran into | B．began with | C．led to | D．came from |
The secretary is very careful and never ___ any little points in her daily work.
| A．overcomes | B．overlooks |
| C．refuses | D．denies |
Jack offered us a big meal when he was leaving the office, but our work ____, we refused it.
| A．not finished | B．had not been finished |
| C．not having finished | D．wasn’t finished |
In the library new books have to be ___ before they are put on shelves for reader’s use.
| A．listed | B．combined | C．classified | D．made |
Your suggestion sounds very good, but there are many ___ difficulties we have to face.
| A．patient | B．popular | C．productive | D．practical |
Having been ___ volunteer in a day-care centre for weeks, Susan feels much sympathy for ___ disabled.
| A．a; / | B．/; a | C．the; the | D．a; the |