Write a few reasons why people need to watch out for there invironment?

In a cooking context, which of the following materials is the best heat conducter?

How should the syntax in this sentence be changed, if at all? the scientists spent years analyzing the results of numerous medical studies meant to identify the cause of the disease. no change the scientists spent years looking at the results of a variety of different medical studies meant to locate the cause of the disease. the scientists spent years reviewing medical study results to find the cause of the disease. the scientists spent years studying the results of many medical studies in order to uncover the cause of the disease.

of the following words means "to make something unnecessary"? who talke constantlyor in na