4) which two reasons listed below are the main reasons that support the building of a dam? a) improve the beauty of an area and create a lake b) create recreation areas and to increase tourism c) provide irrigation water and produce hydroelectric power d) provide irrigation water and allow water to flow more freely

The correct answer is C beacuse it just is

the correct option is C) Provide irrigation water and produce hydroelectric power.

Explanation: The others are not so certain because dams also kill fauna and fish. Nowadays, engineers are trying to build more eco friendly dams.

saving account is right

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