题目选项分析

Standing twelve feet tall, weighing nine thousand pounds, and wielding seven-inch claws, Megatherium americanum, a giant ground sloth,may have been the largest hunting mammal ever to walk the Earth.

The giant ground sloth Megatherium americanum, having stood twelve feet tall, weighing nine thousand pounds, and wielding seven-inch claws, itmay have been the largest hunting mammal ever to walk the Earth.