| 1 | The guerrillas kept a close watch on the movements of the enemy. | |
| 2 | And so the first thing I want to do is to test your alertness. | |
| 3 | An observant shop assistant had remembered exactly what the man was wearing. | |
| 4 | keeping alert in the fire is important for people's finding the way out. ; | |
| 5 | While the picture is developing I'm now going to test your real alertness. |