When I saw the beautifully decorated house, I really wondered __________ she could manage that all by herself.
To learn to swim well, ___________.
The next thing he saw was smoke ______ from behind the house.
They began to think about what use could be ______ such materials.
Tom ______ close the window when his attention was caught by a bird.
He has made some spelling mistakes in the paper; ______, they are not serious.