1. Crabs and  Prawns          A. Book lungs

2. Spiders and scorpions     B. Book gills

3. King crab (Limulus)        C. Trachea

4. Insects                             D. Gills

1. Fishes                  A. Internal  fertilization

2. Amphibians         B. Calcareous  eggs

3. Mammals             C. External fertilization

4. Reptiles               D. Eggs laid in water

1. Parallel venation               A. 2 seed coats

2. Dicot plants                      B. Dicot plants 

3. Monocot plants                 C. 1 Seed coat

4. Reticulate venation             D. Monocot plants