Can you imagine that a smart man like him_____ make such a stupid mistake?

 It is hard for me to imagine what I would be doing today if I ________ in love, at the age of seven, with the Melinda Cox Library in my hometown. 

 Why are you doing that? If I ____you, I’d stop.

The boy suggested that Tom ______ the problem another way, and Tom’s expression suggested that he_________. 

"______ the friendship between our two people last forever!", and with this sincere hope, the president concluded his speech.