Grammatical name of which carry a great deal of heavy traffic

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.

the answer is: the start of world war i, and russia’s hopes of benefiting from it

during world war i russian joined due to in their current crisis they were being supported by france and the war was already declared to them by germany, they needed to maintain their political goal and leadership role in the balkans, and is the same feeling that this excerpt evoke the eager of maintain the land value.