I can’t find my dictionary anywhere.— You _____ have lost it while studying in the library.

There are many big trees on ________ sides of the river.

I saw Mr. Smith in the office at ten yesterday morning.—That’s impossible. He _______ an English party with us then.

Last month, three thousand students took part in the _______ sports meeting.

ve is _____to the public, high up the face of a cliff which no one can climb.