Einstein’s most famous theory is ______ we call theTheory of Relativity.

____ you know your potential（潜力）, you have to rely on many other people to get to where you are

ropped in on you at about four, p.m., but you didn’t answer the door.—— Oh, that was probably _________ I was playing badminton in the stadium nearby.

“____either you or he to go there?” –“_____is.”

Bob, can you tell us about your New Year’s resolution—I’m not about it yet.