A whale is no less a mammal than a horse.

I have once seen a live whale.

I've never seen a live whale.

Have you ever seen a whale?

Whales are classified as mammals.

A whale is a mammal.

A whale is a mammal; in other words it feeds milk to its young.

Unless whales are protected, they will become extinct.

The whale is the largest animal on the earth.

Whales feed on small fish.

The whale is well known to be the largest mammal.

Whales are similar to fishes in shape.

It was believed that whales were fish.

The whale is not a fish but a mammal.

Whales feed on plankton and small fish.

The whale is a very large mammal which lives in the sea.

The whale is not a fish but a mammal.

It is believed that whales have their own language.

As likely as not, whales will be extinct by the end of this century.

Fish stocks are declining due to over-protection of whales, so fish that whales can eat should also be protected.