11.   Embrace the Internet and stop killing trees.

12.   Eventually, as both root and trunk thicken, the flow of sap stops, killing the tree.

13.   Even the trees have been killed.

14.   Human interference, mostly in the form of pollution, is killing our trees.

15.   If I cut those roots, will it kill the tree?

16.   If the disease is left unchecked, it can kill the tree.

17.   Lately, the monkeys have taken to stripping the bark off the cedars, which can kill the trees.

18.   Meanwhile, these insects can kill a tree in three years.

19.   Salt kills roadside trees, pollutes wells and corrodes cars, bridges and parking garages, with annual damage estimates running in the billions of dollars.

20.   Sawflies cannot kill a tree, but can weaken it.