If you _____________ your study, I am sure you will make greater progress.
| A．concentrate on | B．concentrate to |
| C．focus to | D．focus at |
He is said to be ___ the office.
| A．fit for | B．fit | C．fit about | D．fit to |
___ he is going to do it or not does not matter .
| A．Whether | B．If | C．When | D．Why |
Hearing the news, Lillte Jim burst into ___
| A．laughing | B．laughters | C．laughter | D．be laughing |
My sister became famous ___ her first short story “The Moon”.
| A．in | B．for | C．on | D．about |
When Lincoln was young , he helped his father ___ the farm.
| A．in | B．on | C．at | D．for |