Answer:
"John hopes the sleeping bag will keep the den dark and the bear calm a bit longer."
Step-by-step explanation:
In the paragraph, John crouches in the den and is trying to see if there is a bear in the den or not. To his surprise, the bear is not only just in the den but is also awake and his head is at the entrance. So, he pulled back and whips the whole of the den with his sleeping bag. He whipped the sleeping bag because he was afraid that the bear might attack him. He hopes that this act might keep the den in dark and the bear calm for some more time.
So, the answer is when John is hoping that the sleeping bag will be able to keep the den in dark and bear calm.