Answer is B. The length of a day on mercury is much longer than Earth
the decomposer is missing. The rabbit is the herbivore, the rasberry bush is the producer, and the owl is the consumer. The decompoer is the only thing not on there.
The numbers 3 and 4 means that there are 3 Nitrogen atoms, and 12 Hydrogen atoms in the chemical formular (3NH4). The 3 coefficient in front of the compound applies to all of the elements while the 4 applies to only hydrogen (H). This means that the compound contains 3 Nitrogen atoms and 12 (4 multiplied by 3) Hydrogen atoms.