She’s already an hour late, What _____to her? A can have happened B may happen C should have happened D may have happened
— Mummy, I have broken my train. 一I told you so. You _______ on it.
You can't imagine that a top student ______ have failed in the college entrance examination.
Thank you for giving me a hand. I ______ in the experiment without your valuable help.
This cake is very sweet. You _____ a lot of sugar in it.
He paid for a seat, when he ______ have entered free.