1. The minister had hardly finished his speech when the earthquake __________(shake) the building.
2. Everybody will be at the office at about 08:30 tomorrow as the meeting __________(start) at nine o'clock.
3. The candidate who we had interviewed before we __________(speak) to any others is still my favorite.
4. While climbing the mountain, we _____________(encounter) a strange animal which I'd never seen before.
5. According to a study, thousands of vending machines ______________(need / modify) before we can use the new coins.