Please help me.I need to finish this.

Marcy is a very good math student, but she seldom studies for tests. as a result, her grade has dropped this semester. this is an example wasting talent getting distracted allowing others to set goals

The double-blind procedure is most for a.random assignment b.the placebo effect c.operational definitions replication d. standard deviations

Coal combustion produces which of the following waste products? i. tar ii. methane iii. electricity i only ii only i and ii ii and iii i, ii, and iii