U words (long sound)

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Across
  1. 2. Green fruit often used in guacamole (7)
  2. 5. Soft, luxurious fabric (6)
  3. 7. Unable to be seen (9)
Down
  1. 1. The loudness or softness of a sound (6)
  2. 3. A secure room for valuables or a gymnastic jump (5)
  3. 4. A natural underground chamber (4)
  4. 5. Southeast Asian country with Hanoi as its capital (7)
  5. 6. A large bird that feeds on carrion (7)