"I've never seen one of those before," Bradley said to Aunt Lisa as they cruised along in her car. He was going to spend two weeks with his aunt before going to summer camp in her state. His parents were away on a month-long business trip.
"What's that, Bradley?" Aunt Lisa asked.
"That thing there, rolling in the wind. It looks like a clump of weeds," Bradley said as he pointed out the window at something going across a flat plain.
"Oh, that's tumbleweed," Aunt Lisa said.
"Is that what it is called?" Bradley asked.
"Yes. It's part of certain plants here that dry and break away from their roots. It tends to tumble in the wind because of all the flat land out here."
"It seems to get going pretty fast," Bradley observed.
"Yes, on particularly windy days you can hardly catch it."
"We don't have it where I live," Bradley said.