According to the passage, coelacanths and lungfish were initially of interest in the study of the evolution of land vertebrates because

Which of the following statements, if true, most weakens the authors' suggestion that the record of X-ray binaries provides evidence for the existence of black holes?

The author suggests that the traditional definition of innovation, of the two definitions discussed, is

With which of the following statements about nanoparticles would the author most likely agree?

It can be inferred from the passage that which of the following is a true statement about the evolution of a species?

The bonobos do not form exclusive mating relationships, not discriminating in their sexual behavior even by sex or age.

One of history's most popular composers, Beethoven composed throughout his entire life; his symphonies -- some composed while deaf -- are quite possibly performed more than any other composer.

Gene therapy, the use of DNA as a drug to treat disease, has potential applications such as improvement of athletes' performance, to treat single gene defects in individuals, and elimination of certain malicious genes from the DNA passed on to patients' offspring.

The events of the 2006 movie Driving Lessons focus on the friendship between Ben, a shy teenaged boy, with an aging and eccentric actress, Evie, when she hires the boy as a companion to assist her in the house and drive her to various appointments.

With a good development team and a dependable brand, the software giant can offer no good explanation for its operating system's failed attempt to thrive, or at least gain a foothold, in a marketplace that is receptive to it.

In the Amazon, the alignment of a fertile ecosystem and isolation from other ecologies during early geological epochs has given rise to a great diversity of species, which, in many genuses, outnumber those in other regions on Earth by 100 to 1.

Japan has a land area similar to California but fully 128 million in population, where 23% are over the age of 65, according to the 2010 census.

In 1021, Murasaki Shikibu completed The Tale of Genji, a work that, spanning over 50 chapters and 400 characters, and which many scholars, judging its psychological complexity, consider the first novel.

Because there are terms of the International Maritime Organization that stipulate that every vessel that gets an identification number also be outfitted with an automatic onboard tracking system, they have partly deterred illegal fishing.

Although they cannot always distinguish between changes limited to one part of the supply chain and those that move through it, most analysts who have watched the market typically have concluded that heating oil prices rise the year after the prices of crude oil rise.

Computer networks that run on distributed servers tend not to possess one or more single points of failure, so that, if one point fails it replaces it, often by the network having more than one backup server available.

In some cases, two clouds may break apart from the collapsing matter that typically forms a star, then holding each other in orbit around their common center of mass as a binary star.

When not augmented appropriately by an increase in protein intake, a weight-lifting regimen may tire muscles without building strength.

Bertrand Russell carried on the fledgling tradition of the philosophy of logic in terms of both its goals and in methods, but he had been ultimately no more successful than his predecessor Gottlob Frege in attempts to ground arithmetic in the precepts of formal logic.

Looking at search engine trends, evidence has been gathered by reporters indicating that, despite recent actions making the practice illegal, American interest in unlocking cell phones is much higher than they had previously thought.