North American gray wolves usually have mixed gray and white fur, but some members of the species have a version of a gene, or gene variant, that gives them a mostly black coat instead. Sarah Cubaynes and her team studied twelve populations of North American gray wolves. They found that the black-furred wolves are more common in areas where outbreaks of distemper virus happen regularly. The team also discovered that the black-furred wolves are more likely to be immune to distemper than the gray-furred wolves are. Taken together, these findings suggest that____

Which choice most logically completes the text?

A) North American gray wolves experience more outbreaks of distemper virus than other wolf species do.

B) the gene variant that results in black fur may be linked to immunity to the distemper virus.

C) the average life span of gray wolves is likely to increase over time because of a particular gene variant.

D) gray-furred wolves will soon replace black-furred wolves across North America

In studying whether jellyfish sleep, researchers Michael Abrams, Claire Bedbrook, and Ravi Nath attempted to answer three questions. ____is there a period each day when the pulse rates of jellyfish decline? Second, do jellyfish respond more slowly to stimuli during that period? Finally, if prevented from sleeping, are jellyfish adversely affected?

Which choice completes the text with the most logical transition?

A) As a result,

B) However,

C) Additionally,

D) First,

To explore how blinking affects social interactions, Dutch researchers observed interactions between human speakers and “listeners” (animated human faces on a screen). The researchers found that when the listeners blinked slowly, the speakers tended to talk for less time. ____quicker blinks were associated with longer talking times.

Which choice completes the text with the most logical transition?

A) By contrast,

B)Specifically,

C) Firstly,

D) For example,

In Gothic architecture, flying buttresses are large arches that help support a building’s exterior walls. Before the Gothic era, cathedrals’ heavy ceilings had to be supported by thick, short walls, but the invention of flying buttresses eliminated this need. ____Gothic cathedrals could be built with thinner, higher walls.

Which choice completes the text with the most logical transition?

A) Similarly,

B) For instance,

C) As a result,

D) Nevertheless,

By 1936, Spanish Romani dancer Carmen Amaya was known all over Spain for her powerful style of flamenco dancing. However, in July of that year, the outbreak of the Spanish Civil War made it difficult for her to perform in her home country. ____Amaya left Spain to perform abroad, dancing for audiences across North and South America.

Which choice completes the text with the most logical transition?

A) In comparison,

B) As a result,

C) First of all,

D) For example,

With her room-sized installation The Interstitium, Iranian American artist Laleh Mehran succeeded in creating a space that felt, as intended, both “familiar and distant.” ____with a video screen placed at the far end of the coal slag-encrusted room, her installation was reminiscent of a typical movie theater—albeit one found in a subterranean coal mine.

Which choice completes the text with the most logical transition?

A) Next,

B) Nevertheless,

C) Indeed,

D) Instead,

The chemical trimethylamine N-oxide not only gives fish their fishy smell but also protects them from crushing hydrostatic pressure in deep waters. Trimethylamine N-oxide strengthens the bonds between water molecules in a fish’s body. ____these water molecules maintain their linked structure at extreme depths, thus preventing pressure-related damage.

Which choice completes the text with the most logical transition?

A) Nevertheless,

B) For instance

C) However,

D) As a result,

Earth’s auroras—colorful displays of light seen above the northern and southern poles—result, broadly speaking, from the Sun’s activity. ____the Sun releases charged particles that are captured by Earth’s magnetic field and channeled toward the poles. These particles then collide with atoms in the atmosphere, causing the atoms to emit auroral light.

Which choice completes the text with the most logical transition?

A) Nevertheless,

B) Similarly,

C) Specifically,

D) Hence,

The more diverse and wide ranging an animal’s behaviors, the larger and more energy demanding the animal’s brain tends to be. ____from an evolutionary perspective, animals that perform only basic actions should allocate fewer resources to growing and maintaining brain tissue. The specialized subtypes of ants within colonies provide an opportunity to explore this hypothesis.

Which choice completes the text with the most logical transition?

A) Subsequently,

B) Besides,

C) Thus,

D) Nevertheless,

Laetitia Ky’s hair is her art. Inspired by hairstyles from various African tribes, the Ivorian artist uses wire and thread to sculpt her hair into all kinds of shapes. ____she once made her hair into the shape of the continent of Africa—including the island of Madagascar!

Which choice completes the text with the most logical transition?

A) For example,

B) Elsewhere,

C) Soon,

D) However,