| 1 | Due to the noise, he ( ) on his homework. | |||
| is difficult to concentrate | is difficult concen-trating | has difficulty to concentrate | has difficulty concen-trating | |
| 2 | It was brave ( ) her to give a speech in front of hundreds of people. | |||
| for | to | with | of | |
| 3 | ( ) present at the conference were all against the project. | |||
| That | Those | There | These | |