Answer:
The error is in the use of "was" before the subjects "pollution and disease".
The incorrect verb is "was".
The correct sentence will be <em>"pollution and disease were to blame for the decimation of the Chesapeake Bay oyster population in the 1990s"</em>.
Explanation:
When we say the subject-verb agreement, then it means that the helping verb used is dependent on the number of the subject(s). This means that if the subject is singular, then the verb will be singular, and if it is plural, then the verb also becomes plural.
Now, taking the given sentence, we can see that the subjects are <em>"pollution and disease"</em>, which is plural in nature. The use of "and" makes it plural, thereby making the use of the singular verb "was" wrong.
Thus, the correct sentence will be <u><em>"pollution and disease were to blame for the decimation of the Chesapeake Bay oyster population in the 1990s".</em></u>
The line of the poem which expresses the theme that youth passes quickly is:
“ But only so an hour”
The poem “Nothing Gold Can Stay,” by Robert Frost is about the inevitability of things which are beautiful and soothing. Frost explores the theme that although youth is beautiful and charming, it will be lost someday. He shows this change with the examples taken from nature. He adds that the flowers which bloom in spring season will be lost and the children will grow and turn into adults. He takes the example of the Fall of man to show that every beautiful thing can be turned down.