Tom was walking along the riverside when he heard someone calling him from behind. He turned around_______ found nothing.
The students were all tired, but ________ of them stopped to have a rest.
The family is very poor and they can’t________ to buy a computer for him.
We live in a world _______ colours.
Not only the students but also their teacher _______ about the four people.
---Have you found ________ in the grass, Millie? ---No, not yet.