instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Collision frequency is greater for homogeneous category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'.
answer:
Collision frequency is greater for what category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'?


question:
Once a plant cell becomes specialized, divide can they no longer do.
answer:
Once a plant cell becomes specialized, what can they no longer do?


question:
Limiting the number of cars on the roads would most likely improve the air quality in large texas cities.
answer:
Which of these would most likely improve the air quality in large Texas cities?