Commas with Nonessential and Parenthetical Elements

In the early nineteenth century, a Cherokee silversmith named Sequoyah set out to create a written language for his people. Sequoyah's writing system which he painstakingly developed, consisted of eighty-five characters representing distinct syllables. Within a few years, literacy rates among the Cherokee rose dramatically, demonstrating the success of his invention.

Which of the following choices best punctuates the underlined portion of the sentence?

In 1609, Galileo Galilei constructed an instrument that would revolutionize astronomy. The telescope that Galileo built, which had a magnification of three times, helped him discover the four largest moons of Jupiter. These observations challenged the geocentric model of the universe.

Which choice best punctuates the underlined portion of the sentence?

In the early twentieth century, a new musical style emerged in the vibrant neighborhoods of New Orleans. The musicians who performed in early jazz brass bands, which were popular in New Orleans often relied on improvisation rather than written sheet music. This innovative approach helped popularize the genre across the nation.

Which of the following alternatives to the underlined portion is grammatically correct?

The museum houses thousands of historical artifacts from ancient civilizations. The obsidian [underline]blade, which was discovered in a volcanic region, is[/underline] the collection's highlight. Archaeologists believe it was used in royal ceremonies.

Which of the following is the best version of the underlined portion of the sentence?

In the seventeenth century, Artemisia Gentileschi overcame significant barriers to become one of the most celebrated painters of the Baroque era. Her masterpiece , a dramatic rendering of Judith slaying Holofernes, showcases her brilliant use of intense light and shadow. Today, art historians recognize this work as a defining achievement of seventeenth-century art.

Which choice best punctuates the underlined portion of the passage?

Botanists were shocked in 1994 when they discovered a small grove of Wollemi pines in a remote Australian canyon. The prehistoric trees, which were previously thought to have been extinct for millions of years, survived in deep sandstone gorges. Conservationists immediately began a propagation program to safeguard the species.

Which of the following is the best punctuation for the underlined portion of the sentence?

The following passage is an excerpt from a history of Mayan archaeology.

For decades, Mayan scholars believed that the hieroglyphs carved into stone stelae recorded only mythical stories and astronomical tables. In 1960, Tatiana Proskouriakoff published a breakthrough study of the glyphs at Piedras Negras. She demonstrated that the monument inscriptions, which were carved at regular intervals of five hotuns, actually detailed the births, accessions, and victories of historical rulers.

Which choice best punctuates the underlined portion of the sentence?

The following passage is an excerpt from a biography of a historic figure.

When the chief engineer of the Brooklyn Bridge fell ill in 1872, his wife Emily Warren Roebling stepped in to manage the daily operations of the monumental project. The engineers who drafted the daily blueprints, which were critical to the project, met with Emily Roebling every morning to receive instructions. Ultimately, her dedication ensured the successful completion of what was then the longest suspension bridge in the world.

Which of the following is the most effective punctuation for the underlined portion of the passage?

The following passage is an excerpt from an essay on the history of science.

In the mid-twentieth century, the scientific community remained skeptical of plate tectonics. Marie Tharp, a pioneering cartographer, created the ocean map that proved the theory of continental drift. Her meticulous work revealed the dramatic topography of the ocean floor, transforming geology forever.

Which choice is the correct punctuation for the underlined portion of the sentence?

Many plant species rely on mutualistic relationships with fungi to absorb nutrients from the soil. The ghost orchid, which lacks leaves and chlorophyll, depends entirely on mycorrhizal fungi for survival. Without this symbiotic partner, the orchid seeds would fail to germinate.

Which choice best punctuates the underlined portion of the sentence?

In 1928, Scottish biologist Alexander Fleming made an accidental discovery in his laboratory. A strange mold, which grew in a neglected petri dish, was killing the surrounding bacteria. This chance observation led to the development of penicillin, the world's first modern antibiotic.

Which choice best punctuates the underlined portion of the sentence?

The following passage contains an underlined portion.

In the mid-nineteenth century, the visionary mathematician Ada Lovelace collaborated with inventor Charles Babbage on his mechanical calculator, the Analytical Engine. Lovelace recognized that the machine had applications beyond mere calculation, translating an article on the engine and appending her own extensive commentary. Her detailed notes, which researchers now consider the first computer program described how the machine could compute a sequence of complex numbers.

Which of the following choices represents the correct punctuation for the underlined portion?

Read the passage below and answer the question that follows.

Located off the coast of Australia, the Great Barrier Reef is the largest coral reef system on Earth. The Great Barrier Reef, which stretches over 1,400 miles is home to thousands of unique marine species. Protecting this fragile ecosystem is a primary concern for modern marine biologists.

Which of the following choices represents the correct punctuation for the underlined portion of the sentence?

For centuries, Mayan hieroglyphs remained a profound mystery to scholars who struggled to decipher the complex symbols. A breakthrough came when Yuri Knorozov, a Soviet linguist, proposed that the glyphs that were carved in stone, which had puzzled scholars for years, could finally be deciphered using a phonetic key.

Which choice best punctuates the underlined portion of the sentence?

The architect Antoni Gaudí designed several whimsical buildings in Spain. The historic cathedral, which is located in Barcelona, remains unfinished today. Despite this, it attracts millions of visitors every year.

Which choice best punctuates the underlined portion of the sentence?

During the late Renaissance, a guild of Venetian glassmakers guarded their secret formulas with fierce protectiveness. Any artisan who dared to share these methods, which were considered state secrets, with outsiders faced banishment or worse. Consequently, the island of Murano became the undisputed capital of luxury glasswork in Europe.

Which of the following options represents the correct punctuation for the underlined portion of the sentence?

The following passage contains an underlined portion.

In the early twentieth century, a group of artists shocked the Paris art world with their expressive, non-naturalistic use of color. The French painter Henri Matisse, who pioneered the Fauvism movement, created art that was characterized by bold colors and simplified shapes. His revolutionary style challenged traditional academic representation and paved the way for modern abstract art.

Which choice is the best version of the underlined portion of the passage?

The local community center recently launched a rooftop garden project to promote urban sustainability. The garden, which features solar-powered irrigation, grows organic vegetables for nearby families. Volunteers hope this initiative will inspire other neighborhoods to start their own green spaces.

Which of the following choices is the correct punctuation for the underlined portion of the sentence?

Astronomer Annie Jump Cannon developed a system to organize stellar spectra. The system that she created, which became the standard for modern astrophysics, helped catalog hundreds of thousands of stars. Her work laid the foundation for future generations of astronomers.

Which choice best punctuates the underlined portion of the sentence?

Astronomers studying the remote galaxy cluster observed a massive distortion in the surrounding space. The gravitational lens, which acts like a giant magnifying glass in space, allowed them to view stars from the early universe. This discovery could help researchers map the distribution of dark matter across the cosmos.

Which of the following is the best punctuation for the underlined portion of the passage?