The answer is: [C]: past .
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Note: The "underlined verb" has to be "made"; since "made" is the ONLY verb in the sentence given.
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The answer to this is yes because diffusion is the movement of particles from high concentration to low concentration. As the smoke rises at one corner of the room soon it spreads all over the room which is simply diffusion.
Muse, Greek Mousa or Moisa, Latin Musa, in Greco-Roman religion and mythology, any of a group of sister goddesses of obscure but ancient origin, the chief centre of whose cult was Mount Helicon in Boeotia, Greece. They were born in Pieria, at the foot of Mount Olympus. Very little is known of their cult, but they had a festival every four years at Thespiae, near Helicon, and a contest (Museia), presumably—or at least at first—in singing and playing.
The third answer is correct (starting from top to bottom)