Turn the given fact into a question by a simple rearrangement of words. This typically involves replacing some part of the given fact with a WH word. For example, replacing the subject of the provided fact with the word "what" can form a valid question. Don't be creative! You just need to rearrange the words to turn the fact into a question - easy! Don't just randomly remove a word from the given fact to form a question. Remember that your question must evaluate scientific understanding. Pick a word or a phrase in the given fact to be the correct answer, then make the rest of the question. You can also form a question without any WH words. For example, "A radio converts electricity into?"

Fact: reproduction requires pollen.
what is required for reproduction?

Fact: Speed is controlled by pushing on bikes pedals.
What is controlled by pushing on bike pedals?

Fact: the chemical opposite of photosynthesis is when cells convert oxygen and carbs into carbon dioxide, water, and energy.

The opposite of when cells convert oxygen and carbs into carbon dioxide, water, and energy is what?