user
I never can go up, I'm always coming down.   Increasing my speed at first, then decreasing near the ground. 
A: parade ground
B: avalanche
C: invitation
D: rocks
E: account
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

B

<|end_of_solution|>