Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Input: Consider Input: Low energy causes waves to bring sand up onto the beach during summers.

Output: What causes waves to bring sand up onto the beach during summers?


Input: Consider Input: A concave lens is thicker at the edges than it is in the middle.

Output: What type of lens is thicker at the edges than it is in the middle?


Input: Consider Input: Elements below the second period, such as silicon, do not form n bonds as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements.


Output: Elements below the second period, such as silicon, do not form what as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements?