How do you think _________that he was an hour late on such a short journey?
At present the hotel is almost empty , but I’m sure things will start to _____ in the spring .
--- How much vinegar(醋) did you put in the soup ? --- I’m sorry to say , _______. I forgot .
_______ all the inventions have in common is ______ they have succeeded .
We _______ each other the best of luck in the examination .
_________ recent report stated that the number of Spanish speakers in the US would be higher than the number of English speakers by ______ year 2090.