Read the following passage. Then choose the best answer for each question.

The time when human crossed the Arctic land bridge from Siberia to Alaska seems remote to us today, but actually represents a late stage in the prehistory of humans, an era when polished stone implements and bows and arrows were already being used and dogs had already been domesticated

When these early migrants arrived in North America, they found the woods and plains dominated by three types of American mammoths. These elephants were distinguished from today’s elephants mainly by their thick, shaggy coats and their huge, upward-curving tusks. They had arrived on the continent hundreds of thousands of years before their followers. The woody mammoth in the North, the Columbian mammoth in middle North America, and the imperial mammoth of the South, together with their distant cousins the mastodons, dominated the land. Here, as in the Old World, there is evidence that humans hunted these elephants, as shown by numerous spear points found with mammoth remains

Then, at the end of the Ice Age, when the last glaciers had retreated, there was a relatively sudden and widespread extinction of elephants. In the New World, both mammoths and mastodons disappeared. In the Old World, only Indian and African elephants survived.

Why did the huge, seemingly successful mammoths disappear? Were humans connected with their extinction? Perhaps, but at that time, although they were cunning hunters, humans were still widely settled and not very numerous. It is difficult to see how they could have prevailed over the mammoth to such an extent

1. With which of the following is the passage primarily concerned?

2. The word “implements” in paragraph 1 is closest in meaning to _____

3. The phrase “these early migrants” in paragraph 2 refers to ____

4. Where were the imperial mammoths the dominant type of mammoth?

5. It can be inferred that when humans crossed into the New World, they ____

6. Which of the following could be best substitute for the word “remains” in paragraph 2?

7. The word “seemingly” in line 9 is closest in meaning to

8. The passage supports which of the following conclusions about mammoth

9. The word “cunning” in line 20 is closest in meaning to

10. Which of the following is NOT true about prehistoric humans at the time of the mammoth’s extinction?

11. Which of the following types of elephants does the author discuss in the most detail in the passage?