In 1899, Swedish chemist Svante Arrhenius developed an equation to answer a long-standing question: why do chemical reactions speed up at higher temperatures? The Arrhenius equation, named for its creator,____an important concept in modern chemistry.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) have remained

B) remain

C) are remaining

D) remains

The human brain is primed to recognize faces—so much so that, due to a perceptual tendency called pareidolia,____will even find faces in clouds, wooden doors, pieces of fruit, and other faceless inanimate objects. Researcher Susan Magsamen has focused her work on better understanding this everyday phenomenon.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) she

B) they 

C) it

D) those

Oglala Lakota poet Layli Long Soldier’s star quilt poems offer an unusually open-ended reading experience. With____eight panels of text stitched together in the shape of a traditional eight-pointed Lakota star quilt, the poems present viewers with a seemingly infinite number of ways to read them.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) their

B) it’s

C) they’re

D) its

Inventor John Friedman created a prototype of the first flexible straw by inserting a screw into a paper straw and, using dental floss, binding the straw tightly around the____When the floss and screw were removed, the resulting corrugations in the paper allowed the straw to bend easily over the edge of a glass.

Which choice completes the text so that it conforms to the conventions of Standard English?

A) screw’s thread’s.

B) screws’ threads.

C) screw’s threads.

D) screws threads’.

The violins handmade in the seventeeth century by Italian craftsman Antonio Stradivari have been celebrated as some of the finest in the world. In close collaboration with musicians, Stradivari introduced changes to the shape of a traditional violin, flattening some of the instrument’s curves and making____lighter overall.

Which choice completes the text so that it conforms to the conventions of Standard English?

A)those

B) one

C) them

D) it