The UFO, with a zigzag movement you couldn't think of as being a plane, flew off into the mountains in the east.

For example, Pepperberg would show Alex an object, such as a green wooden peg or a red paper triangle.

Matter can exist as a solid, liquid, or gas.

I saw a strange moving object in the sky.

I found a strange object lying on the road.

Ancient astronomers did not have instruments to help them see objects in the sky.

Gravity causes objects to have weight.

Gravity is the natural force by which objects are attracted to each other.

Pepperberg can show Alex two objects (for example, a green square and a red square) and ask, "What's different?"

It is unclear in Patterson's experiment whether the output objects fully correspond to the designed models.

The object flew away to the south, giving out flashes of light.

The surface of the object is fairly rough.

Can you describe the object?

The surface of the peculiar object is fairly rough.

These substances are not poisonous in themselves.

To make a web, it starts by making a frame of this silk and fastening it to hard objects, such as trees or fences.

Alex would correctly describe the object and color, even if he had never seen that object before.

Something looking like a UFO made a sudden turn then disappeared into the distant sky.

UFO stands for unidentified flying object.

"What does U.F.O. stand for?" "It means Unidentified Flying Object, I guess."