21.   A display of Christmas trees from different periods.

22.   A tree from China that helps fight cancer may soon find a home in Texas.

23.   Burlap is an overcoat that shields trees from drying wind, scorching sun and branch-breaking ice and snow.

24.   Burn trees from the forests and old floorboards, they are told, store water in a land whose water pumping stations have stopped working.

25.   Bulldozer removed olive trees from an area where a road is to be built.

26.   But weeding out the most economical tree from the deluge of possibilities results in one of those problems that mathematicians call intractable.

27.   Can you raise the tree from seed?

28.   Carefully remove the tree from the container or remove wire or plastic wrapping from a balled-and-burlapped tree.

29.   Disputes often include arguments over harvesting trees from land theoretically held in common.

30.   For half a century, the mill had turned trees from the North Rim of the Grand Canyon into wood products.