One question that scientists have not yet answered is what caused the number of large zebra mussels to decline. How might tracking different parts of the ecosystem over a long time help scientists to answer this question?

Hudson river have a different climate and is not inhabitable by zebra mussels was said by scientist in the 90s. It might be because of increasing water pollution in the Hudson river as their are channels from the cities which meet the river.

a phrase is a set of word that make a sense, an expression formed by two or more words.

" teacher´s dictum on the possession of human "

" made a pile practicing "

" lived to an impressive age and dies "

a clause, in a grammar way is a series of words that have a complete meaning.

" was irritated by the persecution of those who called themselves "