What single-use container uses the least amount of resources from environment

a plastic bottle
a steel bottle
a glass cup
or a paper cup

Paper cup

Explanation:

A paper cup consists of paper and its extracts that are derived from plants and trees. In this regard some people can claim that paper cup uses the maximum resources but this is not the case. Though paper is derived from trees and plants, its overall life cycle cost is very low. Being a natural product its production, decomposition, reduction, re-usage and recycling involves the least cost as compared to a glass, plastic or steel cup or bottle.  

Thus, option D is correct

the animal that would be cutest if scaled down to the size of a cat? elephant

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.