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).

Paragraph: Wave frequency can be measured by counting the number of crests or compressions that pass the point in 1 second or other time period. The higher the number is, the greater is the frequency of the wave.
 Question: If there are more crests coming through, there will be _____ wave frequency. 
 Choices: A)more 
B)less
more

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
higher

Paragraph: At higher concentrations, particles of reactants are crowded closer together, so they are more likely to collide and react.
 Question: If Mona is filling a balloon with helium and she adds more gas to it, what happens to the likelihood that the helium particles will collide with each other? 
 Choices: A)more likely 
B)less likely

more likely