Hello there, for the first it should be c.gathers. For the second it should be a.birds. For the last one it should be b.stored
Explanation:
the first, gathers, makes the most sense
the second, birds, it's this one because you know that bird's like this is plural and it means bird is. And bird is does not make sense.
the final one, stored, just sounds the best and I hope I am correct on this one but I'm not 100% sure on this one.
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