How might a drought affect a grassland food food web? which trophic level would the drought affect the most? expalin your answer

The uppermost trophic levels would be affected the most. This is because drought reduces the coverage of plants (producers) in a habitat. This therefore reduces the numbers of primary producers in the environment. This effect goes up the food chain and is exacerbated by the fact that energy is lost up the food chain during conversion of biomass from one tropic level to another (because this conversion is highly inefficient)  

i'd say that the moon rock is about 2.2 billion years old.