Task: Text Simplification
Input (English): historically mills were powered by hand -lrb- mortar and pestle -rrb- , working animal , wind -lrb- windmill -rrb- or water -lrb- watermill -rrb-.
Output (English): with reference to past events , mills were powered by hand -lrb- mortar and pestle -rrb- , working animal , wind -lrb- windmill -rrb- or water -lrb- watermill -rrb-.