In the paragraph box, write the main idea of the paragraph below. Acids in concentrated form are very dangerous chemicals to work with. For example, hydrochloric acid has been known
to eat through just about anything, including metal. Acids do appear in the foods you eat. Will the acid harm you? Not if
you eat a balanced diet. But with highly-acidic foods, you sure know the acid is there. It's what makes lemons so sour
main idea:

Acids in concentrated form are very dangerous chemicals to work with.

Explanation:

One way to identify main ideas is to analyse which ideas in the paragraph are derives from another one, then identity that another one, bigger idea. So, the main idea is the one that generalise all the specific points.

Just, remember that those specific points are written to explain and support the main idea. In this all specific points support that ''Acids in concentrated form are very dangerous chemicals to work with''.

Explanation:

i have heard the mermaids singing, each to each.

i do not think they will sing to me

he is suggesting that this widow is a strong woman, who is giving constructive criticism and she has enough to worry about, and she takes care of him, so he does not take it to heart.