Was it near the white building, if I may ask, ____Martin Luther King gave the speech “I have a dream”

Would you like some candies–_______. I have got a sweet tooth.

He was about to cross the street ______ he heard his name ______.

When I first got to Harvard, my awkward English brought me great trouble.——Oh, dear, it _______a struggle for you to keep up with other students.

Excuse me. Is this the right way to the Summer Palace?— Sorry, I am not sure. But it ______ be. [ ]