According to Naomi Nakayama of the University of Edinburgh, the reason seeds from a dying dandelion appear to float in the air while blank is that their porous plumes enhance drag, allowing the seeds to stay airborne long enough for the wind to disperse them throughout the surrounding area.
Which choice completes the text so that it conforms to the conventions of Standard English?
falling,
falling:
falling;
falling
Choice D is the best answer. The word “falling” occurs in the middle of a clause and isn’t part of a supplement, so we don’t need any punctuation after it. We can see this more clearly if we simplify the rest of the sentence: “The reason seeds appear to float while falling is that their plumes enhance drag.” .
Choice A is incorrect. This doesn’t complete the text in a way that conforms to the conventions of Standard English. The word “falling” occurs in the middle of a clause and isn’t part of a supplement, so we don’t need any punctuation after it. We can see this more clearly if we simplify the sentence: “The reason seeds appear to float while falling is that their plumes enhance drag.” . Choice B is incorrect. This doesn’t complete the text in a way that conforms to the conventions of Standard English. The word “falling” occurs in the middle of a clause and isn’t part of a supplement, so we don’t need any punctuation after it. We can see this more clearly if we simplify the sentence: “The reason seeds appear to float while falling is that their plumes enhance drag.” . Choice C is incorrect. This doesn’t complete the text in a way that conforms to the conventions of Standard English. The word “falling” occurs in the middle of a clause and isn’t part of a supplement, so we don’t need any punctuation after it. We can see this more clearly if we simplify the sentence: “The reason seeds appear to float while falling is that their plumes enhance drag.” .