You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").

Paragraph- Sent 1: The highest point of a wave is the crest.
Sent 2: The lowest point is the trough.
Sent 3: The vertical distance between a crest and a trough is the height of the wave.
Sent 4: Wave height is also called amplitude.
Sent 5: The horizontal distance between two crests is the wavelength.
Sent 6: Both amplitude and wavelength are measures of wave size.
Sent 7: The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows.
Sent 8: The greater each of these factors is, the bigger a wave will be.
Sent 9: Some of the biggest waves occur with hurricanes.
Sent 10: A hurricane is a storm that forms over the ocean.
Sent 11: Its winds may blow more than 150 miles per hour!
Sent 12: The winds also travel over long distances and may last for many days. 
Question: When concerning wave height, what are the highest and lowest points called??.
1, 2.