There is no possibility ______ all the students can pass the college entrance examination.

The Burj Khalifa in Dubai is 828 meters high and there is no doubt        it’s the tallest building in the world. 

The question came up at the meeting _______ we had enough money to change the environment

That’s the new machine ______ parts are too small to be seen.

Do you have any idea of the reason _____ he referred to？