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

Ex Input:
Hybridization model model helps explain molecules with double or triple bonds.

Ex Output:
Which model helps explain molecules with double or triple bonds?

Ex Input:
Simple carbohydrates can be classified in terms of chain length.

Ex Output:
Which carbohydrates can be classified in terms of chain length?

Ex Input:
The voyager 1 spacecraft visited saturn in 1980.

Ex Output:
What planet did the voyager 1 spacecraft visit in 1980?