Answer:
Soldiers line up spaced with pride. Two long rows lined side by side. One sole unit can decide, if the rows will unite or divide.
A nut cracker up in a tree.
In we go, out we go. All around and in a row. Always, always steady flow. When we'll stop, you'll never known. In we go, out we go.
A leathery snake, with a stinging bite. I'll stay coiled up, unless I must fight.
What can be measured but not seen?
What did the piece of wood say when he saw the screwdriver and screws approaching?