Ques: More recently, the death rate has fallen because of the availability of more food and medical advances. In ancient times, there was worse medicine. This means there was a lower or higher death rate?
Ans: higher

Ques: At higher temperatures, particles of reactants have more energy, so they move faster. Tom lowered the temperature of a reactant in a lab. The particles in the reactant now have less or more energy?
Ans: less

Ques: Different types of rocks weather at different rates. More resistant types of rocks will remain longer. When Dan went to the beach, he found rocks that had not been eroded. Some rocks were quite weathered though, so those must have a resistance that is higher or lower?
Ans: lower

Ques: By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher. If Mary is building a rocket and she wants it to fly as high as possible, what should she do to the mass of the rocket increase it or decrease it?
Ans:
decrease it