The boys are playing________the edge of the river.
Facts prove that the world’s economic development is not a win-lose game but one in which all ________ be winners.
When we lived in that village, we ________ often play together in the river there.
—Isn’t that your boss over there?—No, it ________ be him. I’m sure he is in the office now.
How ________ you say that you really understand the whole text if you have covered only part of it?
—Many houses near the airport were destroyed by the wind.—Well, the wind ________ have been very strong.