instruction:
You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).
question:
Paragraph: By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher.
 Question: David is getting ready to fly into space on a rocket. As the rocket shoots upwards, part of the mass falls away, allowing the rocket to go 
 Choices: A)higher 
B)lower
answer:
higher


question:
Paragraph: The higher up a food chain that humans eat, the greater the levels of toxic metals they take in.
 Question: If Jim eats animals that are lower on the food chain, the amount of toxic metals that enter his body are 
 Choices: A)greater 
B)smaller
answer:
smaller


question:
Paragraph: Lower temperature and higher salinity yield the densest water.
 Question: When water starts to boil it becomes 
 Choices: A)more dense 
B)less dense
answer:

less dense