The Amazon rainforest produces a significant share of the world’s oxygen. Because its trees and plants ______ carbon dioxide and release oxygen through photosynthesis, scientists often refer to the Amazon as "the lungs of the Earth."

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

In 1928, scientist Alexander Fleming noticed something unusual in his laboratory. A mold growing on one of his petri dishes ______ the bacteria around it, a discovery that eventually led to the development of penicillin.

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

Chef Maria Gonzalez opened her first restaurant in Austin, Texas, in 2015. Since then, ______ has expanded the business to include three additional locations across the state.

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

The students in Mr. Park’s biology class are completing a semester-long project on local ecosystems. Each student ______ a different habitat, such as a pond, a meadow, or a wooded trail, and will present findings to the class in May.

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

Researchers at a wildlife center in Montana have been tracking the movements of gray wolves across the northern Rockies. ______ data shows that wolf packs travel an average of thirty miles per day during the winter months.

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

Last summer, a team of archaeologists ______ a collection of ancient coins near the coast of Sicily. The coins, which date back to the third century, are believed to have been part of a Roman merchant’s savings.

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