1. The materials science laboratory ---- an electron microscope so sophisticated that researchers from three neighbouring universities regularly book time on it.

2. The shuttle bus linking the north campus to the city centre ---- every twenty minutes throughout the academic year, so students seldom bother to consult the printed timetable.

3. Normally a field ecologist who spends her summers deep in the Amazon basin, Dr. Alvarez ---- almost all of her working hours in the laboratory at the moment, since seasonal flooding has made the study site impossible to reach.

4. Nowadays even the most cautious geologists ---- the theory of plate tectonics to be beyond serious dispute, although the idea was dismissed as fantasy for the best part of half a century.

5. I must ask to be left off the programme for Friday morning, as I ---- a delegation of visiting scholars around the excavation trenches at ten, and the arrangement was made weeks ago.

6. Although the museum's newly opened east wing ---- more than three thousand artefacts from the late Bronze Age, no more than a tenth of them can be put on display at any one time.

7. The number of applications to the archaeology programme ---- sharply at present, largely because a popular documentary series has drawn public attention to the recent excavations in the region.

8. Although the two beetle species ---- virtually identical to the naked eye, taxonomists ---- perfectly well that they belong to entirely different genera.

9. Whenever he prepares a béarnaise for the tasting menu, the chef ---- the sauce at least four times, since he insists that it ---- unpleasantly sharp if the vinegar goes into the pan too early.

10. I am afraid I must miss the faculty lunch on Thursday: I ---- the external examiner at one o'clock that day, an appointment we arranged only last week, and I ---- no way of moving it at such short notice.