最佳选项，使短文通顺，结构完整，其中有一项是多余选项。
Nature is full of great ideas.
Many blind people use canes to move around. They tap their canes on the ground in front of them to feel if anything is in their way. One amazing invention was a new cane to help blind people. It helps them move around more safely. This invention was an idea from bats. These signals（信号）are almost the same as the bats use when they fly.
How bats get around
Bats make sounds when they fly at night. People cannot hear these sounds, but they help bats fly in the dark. Bats send sound waves out of their mouth or nose. These sound waves hit objects around them. Then they come back as an echo. The echo tells bats how far away things like trees are.
An amazing idea
The scientist who invented the new cane watched how bats fly. He added something that sends and receives sound waves. Finally, he tested the cane. It worked!
The cane sends out signals. When an echo is sent back, the cane's handle vibrates（振动）. This helps the person holding the cane know how far away an object is. They will also know how big the object is.
This cane shows that great ideas really can come from nature.
A. How the cane works
B. Then he built a lightweight cane.
C. It also helps them know where to find food to eat.
D. The cane works by sending out sound waves or signals.
E. People will get more new ideas from the bats and other animals.
F. Some inventors get ideas from nature to make some useful things.
