Can someone explain why the it.

Which is an advantage to using nonrenewable resources? a. they can be cheaper. b.they can have a lower impact on the environment. c.they can be used up rapidly. d.they can contribute to global warming.

When your working with the passage-based reading questions on the psat do all of the following except. a)make sure you read each question throughly. b) try to answer each question before you look at the answers. c) plan to spend most of your time reading the passage. d) make sure your answer choice is the most correct number me

D/dx(1+x^4+x^6/x^2+x+1) a)2x-1 b)2x+1 c)2 d)0