He has been _______ for three weeks. We’d
better find another person to fill his place.
| A．absent | B．left | C．gone | D．resigned |
She seated herself at a small table in the restaurant, waiting _____.
| A．serving | B．to serve |
| C．served | D．to be served |
Most online classes let students learn _____ their own pace.
| A．at | B．to | C．from | D．by |
_____the size of the universe, some researchers believe that there is life beyond our planet.
| A．Consider | B．To consider |
| C．Considered | D．Considering |
The trains leave every 15 minutes; if you miss ____ , you don’t have to wait long for another.
| A．it | B．this | C．one | D．some |
Mr. Sawyer started his career at Stanford University, _____ he became Professor of Physics in 2002.
| A．which | B．where | C．when | D．that |