. Some animals are in danger, and the scientists are doing ___ they can ___ them.

I’d prefer _______ if I didn’t have to get up early on Sundays. 

Wherever he is, he makes ______ a rule to give his mother a call every day.

They produced two reports, ______ of which contained any useful suggestions.

    in the regulations that you should not tell other people the password of your bank account.