The speaker is talking about the water. During winter, the water enters the cracks and freezes and expands. It breaks the stone and makes cracks and when the water melts the holes are bigger. What he is describing is mechanical weathering which is common in nature.
You did not provide the excerpt but I wound it and the correct answers are the following two sentences:
1.<span>For once, at least, I grasped the mental operations of the Morlocks.
Here we see that they do possess a kind of intelligence, maybe at first strange and unclear but it is there, no matter how strange it might seem.
2.</span><span>I was surprised to find it had been carefully oiled and cleaned.
Here the Time Traveler has found his Time Machine and he finds that the Morlocks had tried to grasp its function and its purpose. They have taken it apart and then cleaned and oiled it, which suggests they know somethings about how the machine work.
</span>
Answer:
Behind the classic car
Explanation:
Behind is one of the words that can start a prepositional phrase.
I actually read two of those books and it was the magician's nephew and the yearling. I liked the magician's nephew better than the yearling.
The author is J. B. Priestley