Which two methods can a reader use to identify the main idea of a text? look for a common point among all sentences. look for a sentence that states the main idea. analyze the vocabulary used in the text. figure out the target audience of the text.

Read the following excerpt from "the city without us" by alan weisman: almost every other compound in nature contracts when frozen, but h20 (water) molecules do the opposite, organizing themselves into elegant hexagonal crystals that take up about 9 percent more space than they did when sloshing around in a liquid state. pretty six-sided crystals suggest snowflakes so gossamer it's hard to conceive of them pushing apart slabs of sidewalk. which statement best describes the effect of the metaphor on the excerpt's meaning? o a. it likens h2o molecules to hexagonal crystals, which are actually larger than people imagine. o b. it makes the frozen crystals seem like friends to the city to contrast with what a deceitful foe they are. o c. it compares the sloshing liquid to a river of water able to push apart the sidewalk o d. it compares the frozen crystals to delicately lacy snowflakes having an unexpected strength (apex)