"Astonishing" and "astounding" are synonyms. The other words, "astronomical," "astral,"  "stellar," and "celestial," all describe the sky, stars, and space! Note that astronomical and astral share a root!

The words "typical" and "representative" can be used to describe something with distinctive qualities. The other words do not have meanings that are as closely related those of "typical" and "representative." In fact, the other answer choices are antonyms of the word "typical."

The words "simple" and "facile" are synonyms. The other words do not have related meanings. "Rude" and "rebellious" are somewhat related to each other but not to the word "simple." "Symptomatic" is not at all relevant, as it is a medical term referring to showing symptoms of a disease or illness. Finally, the word "complex" is actually an antonym of the word "simple."

"Orthodox" means "traditional," according to the book, or conservative.

"Apocryphal" means questionable, fake, inaccurate.

"Effusive" means gushing, profuse or unrestrained.

"Toilsome" means difficult or laborious. 

"Secular" means not spiritual or religious.

The adjective "woeful" means terribly sad and pitiful, pathetic and tragic. Additionally, "repulsive" means gross, disgusting, not attractive; "frantic" means hurried, stressed; "sturdy" means reliable, strong and firm, unlikely to fall over or break; "unhinged" means disturbed, mentally imbalanced, crazy.

"Sporadic" is an adjective defined as occurring at irregular intervals. The term "occasional means occurring, appearing, or done infrequently. This makes "occasional" the correct answer as a synonym "sporadic."

The correct answer is "varied." "Eclectic" is an adjective defined as broad and diverse range of sources.

Varied means showing "variation or variety," making it a synonym of "eclectic."

The noun and adjective "aggregate" refers to the sum of multiple parts, the total, the whole. To "aggregate" means to form or calculate a whole from multiple parts. Additionally, "mutual" means shared; "unreliable" means not reliable, not trustworthy, not responsible.

The adjective "rickety" means shaky, unsteady, poorly made and likely to fall. Additionally, "implied" means not directly stated, but suggested; "improbable" means not likely to happen; "indecisive" means hesitant, not able to decide between two or more options.

The adjective "engaging" means captivating, charming and appealing, interesting, worthy of attention. Additionally, "meticulous" means paying close attention to detail, hard-working; "repulsive" means not attractive, disgusting; "cohesive" means fitting well together, well-matched; "comprehensive" means complete, thorough, not omitting anything.