I am ashamed, sir, that I wasted a lot of hours _______I should have studied at school.
The volunteers try to convince people _____ the fact that some species are in danger of _____.
Across the river _____.
_____ all the demands had been refused _____ to go on strike.
The temperature has _____ heavily, which doesn’t _____ the growth of the crops.
You should keep an eye ______ him, for I have lost faith ______ him.