The dog searched for its bone.
This collection of nuts contains pecans, walnuts, and almonds.
The camera lens was broken by the fall .
The pool in my back yard contains a lot of leaves and sediment. This is a good sentence for the word sediment.
The hydrological cycle contains evaporation as one of its components.
The subject of the sentence typically contains a noun.
A mathematical sentence that contains an equals sign would be called an equation.
This sentence contains the word fortifying.
If you mean what sentence in the paragraph contains the main idea then it would be the topic sentence and the rephrased version of the conclusion.
The compound sentence "I went to the store, and then I visited my friend" contains correct punctuation.
Our monster truck is certain to win the slab pull competition.
If you mean word that contains it then this is my answer: There is a renowned physicist in Arizona that can give you a clue (This is an example from a book of mine.)