These sentences are from the selection. Which two can be considered main ideas of the selection?

Question

A Tree rings and ice cores let scientists reconstruct weather back thousands of years.
To measure faster times, scientists need a faster (and more accurate) way to count time.
C But science often measures time far outside our human perception.
D This happens because different colors of light move at slightly different speeds.
(E) This is 9,162,613,770 (a bit over 9 billion) waves of energy per second.

Answer 1

The two sentences that can be considered main ideas of the selection are:

A) Tree rings and ice cores let scientists reconstruct weather back thousands of years.

C) But science often measures time far outside our human perception.

These sentences present significant concepts regarding scientific measurement and the tools used to understand long-term weather patterns and the abstract nature of time measurement beyond human experience.