It was because he was ill ______ we decided to return home.
Professor Jordon is well known for his _____ into the habits of the common housefly.
I support your decision, but I should also make it clear that I am not going to be _____ to it.
In spite of the thunderstorm, the children slept _____ all night.
They did not find _____ to prepare for the worst conditions they might meet.
The microphone enabled them to keep in touch, in other words, it made it _____ for them to contact each other.