In 1943, Maria Telkes created the first house fully heated by solar power. Her detailed plans showing how solar energy could be used and her process of running tests to see if the system could work without _____ change the traditionally fossil fuel-dependent ways of heating toward a green one.
Which choice completes the text so that it conforms to the conventions of Standard English?
18/27
Click to copy your unique test URL. Return anytime using this link.