In paragraphs, a stated main idea is called the topic sentence. In an article, the stated main idea is called the thesis statement. When the author does not state the main idea directly, it is called an implied main idea.
Answer a seems to be the best choice to use
It is in past tense so the answer is; c. went
Answer:
C He took us down a long, dark hall to a room, where I immediately began to explore the remarkable inventions of the Americans
Explanation: this shows that Ernesto was very interested because of his wanting to explore the inventions of the Americans.