> 3a. That tree isn't big enough to fall because for the tree to fall, it has to be big enough.
3b. That tree isn't big enough to fall because to fall, the tree has to be big enough.
3c. That tree isn't big enough to fell because to fell the tree, it has to be big enough.
3d. That tree isn't big enough to fell because for someone to fell the tree, it has to be big enough.
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