Juan wants to compare the effectiveness of two drugs in treating migraines. he administers drug a to a participant and then drug b to the same participant eight hours later when drug a is still in the participant's system. in this case, the study is contaminated by a effect.

american political culture includes a plenty of focus views and preferences. not all westerns experience the same opinions, of course, but the large preponderance promises to these general ideas, including equality, justice, freedom, individualism, integrity, and difference.

the united states is a democratic republic. residents elect representatives to governmental, nation, and local administration; those deputies create the regulations that command u.s. community. although emptiness in u.s. law needs it, in usage, the administrative system is ruled by executive factions.

during the nancy. probs

answer; the president uses mass media to gain support for policies;

answer; calendar;