Answer: You are missing the decomposers
Explanation: The food web goes in this order, primary producers, primary consumers, secondary consumers, tertiary consumers and then decomposers that break apart dead organisms into simpler inorganic materials.
In this case, the primary producer is the grass. The primary consumers are the rabbit, deer and the rat. The secondary consumer is the fox, and the tertiary consumer is the hawk. However, in this case, there is no decomposer that eats off the hawk's dead body to break it down and provide nutrients for the primary producer again.
