1. While play is important at all levels ofhuman development， _________takes on particular significance when children are five and six years old.
2. During the second and third years oflife， childrengain _________ over their bodies.
3. All brass instruments use a mouthpiece_________ into a long cone-shaped tube.
4. By the mid-twentieth century， United States presidential staffs， _________ had numbered fewer thanten a century earlier， numbered in the hundreds.
5. In 1966 only 60 percent of all five yearolds in the United States attended kindergarten， _________ in 1985 almost 82 percent did so.
6. _________ industries， inventions， and communal endeavors of theShakers， the bestknown is their fine furniture.
7. Most fishes and many reptiles have ribsalong most of the spine， but in mammals _________ only in the ch hest area.
8. Although the habitat of the Americanbeech tree is now confined to the eastern United States and southeastern Canada， _________ extended as far west asCalifornia.
9. Most of North America receives _________some form of continuous plant cover except in the arid and semiarid Southwest.