Birds' singing is sometimes a warning to other birds ______ away.
Many people __________ death in the earthquake as a result of the delay of the food supplies.
In some cases, different approaches __________ the same scientific problem lead to the conflicting theory.
A notice was __________ in order to remind the students of the changed lecture time.
The physics teacher once said that as __________ well-known, thunders __________ make electricity.
I'm sorry to __________ you, but can you tell me how to get to the library?