Why is study of life cycle of silkworm necessary?​

Which best explains why viruses do not have special structures or enzymes that allow them to make their own food? viruses can use energy in living cells that they infect. viruses can replicate inside a host that they infect. viruses can cause contagious illnesses in host cells. viruses integrate their rna or dna into infected cells.

How many types of rock can form from the rock cycle

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks