According to research by el-sheikh in 2007, when children are exposed to adult or marital conflict, they display a biological alarm reaction,: a) their heart rate rises sharply. b) their blood pressure decreases drastically. c) their bodies stop producing dopamine. d) their bodies stop producing norepinephrine.

option A

Explanation:

According to the research done by EI-Sheikh in 2007 on children exposed to adults conflict analysis that children are more prone to alarm reaction which is due to high heart rise.

The main focus of this research is to assess the impact of marital conflict on children. some theories have been used in the research that shown the individual differences in conflict.

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