There's no way of knowing why one man makes an important discovery________another man,also intelligent,fails.
His whole school education _____ only 2 years because of his illness.
The shop _____ until 7 o’clock.
Tonny’s parents thought he was at school, but ______ he was in an Internet bar.
The boy asked his mother _______ go out to relax himself or not.
________ from space, the earth is blue.