The mihrab (or niche) is one of many features that are foundational to traditional mosque architecture and is therefore considered ______ blank aspect of mosque design. Even mosques that exhibit elements of multiple architectural styles, such as the Kocatepe Mosque, which incorporates elements from the Neoclassical Ottoman and modern styles, will also include several of these standard features. Which choice completes the text with the most logical and precise word or phrase?

The following text is adapted from Willa Cather’s 1912 novel Alexander’s Bridge. For the next few days Alexander was very busy. He took a desk in the office of a [Scottish] engineering firm on Henrietta Street, and was at work almost constantly. He avoided the clubs and usually dined alone at his hotel. As used in the text, what does the word “constantly” most nearly mean?

Siemowit is said to have ruled what eventually became Poland in the 9th century. Unlike that of Bezprym or other well-attested figures from early Polish history, Siemowit’s existence has been the subject of debate, as our knowledge of him is ______ blank somewhat dubious oral traditions first written down hundreds of years after the events they describe. Which choice completes the text with the most logical and precise word or phrase?

Parapuzosia seppenradensis, known to have lived in what is now Mexico, and Parapuzosia leptophylla, known to have lived in what is now England, were both ammonites, but P. seppenradensis was much larger than P. leptophylla. Recent research by Christina Ifrim, Nils Schorndorf, and colleagues has suggested that this _______ blank resulted from the unique predator threat faced by each species. Which choice completes the text with the most logical and precise word or phrase?

In their study of fossils of the extinct arthropod Mollisonia symmetrica, Javier Ortega-Hernández, Sarah Losso, and team reported some obvious indications of M. symmetrica ’s nervous system—for example, the animal’s primary nerve cord. They also saw signs of what might be a synganglion, a brain–like mass of nerve tissue, in the animal’s head. This evidence is exciting because it could help us better understand how M. symmetrica is related to other arthropods, such as cave crickets and krill. Which choice best describes the function of the underlined portion in the text as a whole?