1. They left by twos and threes.
2. Soon the guests by twos and threes.
3. They by twos and threes for practice.
4. They came to see me by twos and threes.
5. They came home from church by twos and threes.
6. People came by twos and threes.
7. They came in by twos and threes.
8. The boys come in toghter and go out by twos and threes.
9. The students are coming into the classroom by twos and threes.
10. They walked into the meeting room by twos and threes.