Which sentence contains an adverb clause?
a. only 1,600 covered bridges exist in the world.
b. if you visit pennsylvania, take the self-guided, covered-bridge tour.
c. covered bridges remind us of days gone by.
d. the lehigh valley, in eastern pennsylvania, has seven covered bridges.

The sentence that contains an adverb clause is "The Lehigh Valley, in eastern Pennsylvania, has seven covered bridges."

Explanation:

An adverb clause works as a regular adverb and they belong to the same categories, the sentence D has an adverb clause with an adverbial of place, this clauses commonly start with a preposition which in this sentence is in, this tell the place where the things happen or where the things are, then this one specifically describes where the Lehigh Valley is.

1. read the following excerpt from franklin d. roosevelt's "fireside chat 19":

on the other side of the picture, we must learn also to know that guerilla warfare against the germans in, let us say serbia or norway, us; that a successful russian offensive against the germans us; and that british successes on land or sea in any part of the world strengthen our hands.

remember always that germany and italy, regardless of any formal declaration of war, consider themselves at war with the united states at this moment just as much as they consider themselves at war with britain or russia. and germany puts all the other republics of the americas into the same category of enemies. the people of our sister republics of this hemisphere can be honored by that fact.  

the true goal we seek is far above and beyond the ugly field of battle. when we resort to force, as now we must, we are determined that this force shall be directed toward ultimate good as well as against immediate evil. we americans are not destroyers — we are builders.

analyze the effectiveness of this excerpt. how does it function within the speech as a whole? how does the structure of the excerpt to convey the speech's purpose and key points? support your argument with evidence from the speech. (10 points)

a. inform

explanation:

"how to" tells us that it will explain how to, which means to inform