How do presidents test public opinion before announcing new policies?

They test public opinion by identifying common terms, concepts and beliefs that would be related to their policies.

Explanation:

"Although they rejected the charge of pandering, [...] most politicians tend to respond to public opinion in cynical ways; most of them, for example, use public opinion research not to establish their policies but only to identify slogans and symbols that will make predetermined policies more appealing to their constituents. According to Jacobs and Shapiro, most public opinion research is used to manipulate the public rather than to act on its wishes."

Reference: Encyclopædia Britannica, inc. “Public Opinion and Government.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 2019

sumerians were polytheistic, meaning they believed in many different gods. so, the best answer is c.

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals