"Corrugated" is an adjective that refers to a material, surface, or structure and means "shaped into alternate ridges and grooves." So, "flat" cannot be the correct answer because it is an antonym, not a synonym, of "corrugated." "Grooved," however, is an adjective that means "provided with or having a groove or grooves," and because it is the answer choice closest in meaning to "corrugated," it is the correct answer.

"Durable" is an adjective that means "able to withstand wear, pressure, or damage; hard-wearing," so we need to pick out an answer choice that means something like "able to withstand wear." "Fragile" cannot be the correct answer, then, because "fragile" means the opposite of "durable," so it is an antonym, not a synonym, of "durable." "Hardy," however, is an adjective that means "robust; capable of enduring difficult conditions" and because "hardy" is the answer choice closest in meaning to "durable," "hardy" is the correct answer.

"Firm" meanshard.

"Vacant" meansempty."Empty" is the best choice because it is a part of the definiton for "vacant." Considering the other choices, "lively" meansenergetic,"absent" meansawayormissing,and "evacuate" meansto leave an area because it is dangerous."Evacuate" is not as good a choice because it is a verb, while "vacant" is an adjective.

The word "permeable" meansfull of small holesthat let liquids and objects of a certain size pass through.The best answer choice is "porous," which meansfull of small holes that allow air or liquids to pass through. Considering the other choices, a "sponge" is something that is permeable, "permanent" meanslasting forever andunchanging,and "changing" is an antonym of permanent.

正确的答案是"rough." Both "rough" and "jagged" meanhaving a coarse, uneven surface. The other words all meansmooth, so they are antonyms, or opposites, of "jagged."

正确的答案是"digestible." "Edible" and "digestible" both meanable to be eaten. The other words have to do with food, but do not have to do with the ability of something to be eaten.

"Tepid" meansmoderately warm. The best choice is "lukewarm" because it also meansmoderately warm. Considering the other choices, "scold" meansfind fault with angrily and verbally,"clever" meansintelligentorwitty,and "deep" meansextending far beneath the surface.

"Edible" meansable to be eaten. Notice the suffix "-ible,"which suggests that a word meansable to be something. Watch for suffix and prefix patterns in English, as they can help you figure out the meanings of words you have not seen before.

"Dry" is defined aswithout moisture or liquid. Since "arid" climates are characterized asdry and having little rain, "arid" is the best answer choice. "Moist" is an antonym of "dry."