When brandon was told that he correctly answered 80 percent of the items on a math achievement test, he asked how his performance compared with that of the average test-taker. brandon's concern was directly related to the issue of: ?

The choices are: 
A. ) standardization.
B) predictive validity.
C) reliability.
D) content validity.

The answer is A. standardization. He was comparing his score to other average test-takers. From there he could reflect if the test is a standard  exam for Math. He most probably would see average test takers get approximately at least his score. 

The  ancient egyptians  who  built the pyramids  may have been  able  to move massive stone blocks across the desert by wetting the sand in front of a contraption  built  to pull the heavy objects

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.