The following paragraph has grammatical errors as well as errors in sentence construction. Correct the grammatical errors.

Although penguins look clumsy on land. They are graceful in the water. Their bodies are perfectly suited for swimming and diving. They are a streamlined torpedo shape. Their wings are shaped like flippers penguins use them to propel themselves through the water at speeds up to 30 miles per hour. Use their webbed feet to steer. Most penguins can even swim like porpoises. Leaping out of the water to breathe and then diving back in with one graceful motion. Penguins frequently need to dive deep to catch prey. Sometimes descending to depths of over a thousand feet. The water pressure can be great enough to collapse lungs. Penguins special air chambers in their bodies. When a penguin dives, the chambers squeeze, air is forced into the lungs. The extra air keeps the lungs from collapsing. The chilly waters that penguins prefer would be too cold for most birds, penguins are insulated by waterproof feathers and a thick layer of fat. Penguins more than make up for being awkward on land. By being perfectly suited for the water.

Although penguins look clumsy on land(, they) are graceful in the water. Their bodies are perfectly suited for swimming and diving. They are streamlined torpedo shape. Their wings are shaped like flippers(; penguins)use them to propel themselves through the water at speeds up to 30 miles per hour (and use) their webbed feet to steer. Most penguins can even swim like porpoises(, leaping) out of the water to breathe and then diving back in with one graceful motion. Penguins frequently need to dive deep to catch prey(, sometimes) descending to depths of over a thousand feet. The water pressure can be great enough to collapse the lungs (but) penguins have special air chambers in their bodies. When a penguin dives, the chambers squeeze, (and) air is forced into the lungs. The extra air keeps the lungs from collapsing. The chilly waters that penguins prefer would be too cold for most birds (but) penguins are insulated by waterproof feathers and a thick layer of fat. Penguins more than make up for being awkward on land (by) being perfectly suited for the water.

Explanation:

The corrections needed in the given passage are as follows-

1. The use of a comma after land- this allows the two sentences to join together and flow into one sentence. It gives much more free flow of words in the sentence.

2. Semi-colon after flippers- this provides connectivity for the two independent clauses which have the same thought.

3. Use of "and" after hour connects the two sentences and merged them into a single sentence.

4. A comma after "porpoises" allows the sentence to continue without the need for a new sentence. It also provides an extra detail for the meaning of the statement.

5. use of a comma after "prey' provides another detail in the sentence.

6. The use of "but' after lungs provides contrasting ides to the previous sentence.

7. Addition of "and" after squeeze to connect and provide a smooth flow of words.

8. But" after most birds which presents a contrasting idea.

9. Joining the last two sentences allows the whole passage to be perfectly concluded.  

the author motivation is to show the power of animal-human relationships.

i believe the answer is d