compound words

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Across
  1. 2. band of seven colours in the sky
  2. 6. real brothers and sisters
  3. 8. heavy breakfast
Down
  1. 1. icons for emotions
  2. 3. something which is not possible
  3. 4. used to clean teeth
  4. 5. mixture of fog and smoke
  5. 7. a sea animal of shape of a star