21.   The tree has become his bare arm, stretched impossibly long.

22.   This, coupled with the fact that the trees can become weak and brittle when stressed, increases the likelihood of breaking branches.

23.   This year my ugly duckling tree became a graceful swan.

24.   Trees became flaming torches.

25.   In hot, dry summers every tree becomes a potential tinder box.

26.   The tree became extinct in the sixth century, Hirschfeld said.

27.   The trees became a potent Revolutionary War symbol.

28.   We notice now that palm trees have become the order of the day in cities and towns.

29.   Weakened trees then become vulnerable to attacks by insects and wood-decaying fungi.