Holiday hw

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Across
  1. 4. the most ductile metal
  2. 5. control centre of a cell
  3. 7. smallest cell in existence
  4. 8. hardest substance
  5. 9. ability of an organism to resist infection
Down
  1. 1. process of conversion of dead plant material into coal
  2. 2. give colour to the plants
  3. 3. causes citrus canker
  4. 6. a homogeneous mixture of two or more metals
  5. 7. coal made up of 30 percent carbon