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

A frog develops (a/an) lungs as it changes from a tadpole to an adult frog.
Which of the following structures does a frog develop as it changes from a tadpole to an adult frog?

Hybridization model model helps explain molecules with double or triple bonds.
Which model helps explain molecules with double or triple bonds?

Protocells do you call the membrane-bounded droplets that have some properties of cells.
What do you call the membrane-bounded droplets that have some properties of cells?