Read the passage below and choose the right answer to the following question (choices are better? or worse ): More pollutants mean poorer air quality. After the fire of a pile of tires at the landfill was put out, the reduction of smoke in the air made the air quality better? or worse?
better?

Read the passage below and choose the right answer to the following question (choices are decreased. or increased or ): The higher up a food chain that humans eat, the greater the levels of toxic metals they take in. Sarah ate a salad for dinner, Sarah's levels of toxic metals have decreased. or increased or?
decreased.

Read the passage below and choose the right answer to the following question (choices are young or old ): The upper rock layers are much younger. The rocks that are on the surface of a volcano are young or old?
young