阅读短文，理解其大意，从A、B、C、D四个选项中选出可以填入空白处的最佳选项。At just age 16, Zhen Xin, from Beijing, finished the "Five Great Mountains Challenge" in August—in only five days. She became the 1 person to do it.
The Five Great Mountains Challenge is about climbing China's five greatest mountains—Taishan Mountain in Shandong, Huashan Mountain in Shaanxi, Songshan Mountain in Henan, Hengshan Mountain in Shanxi, and Hengshan Mountain in Hunan—in 100 days.
2 the hot August weather, Zhen did most of her hiking at night."When you can't see what's coming next, many of your3 and worries go away, You're less likely to back down," Zhen explained.
Zhen said the key 4 hiking is one's mentality. Whenever she came across a vendor booth(货摊) along the hiking road, she would 5 herself to carry on until the next one. And whenever she felt she was about to 6 she would reward herself with a drink or some snacks.
Of all the moutains she climbed, Huashan Mountain stood out as her favorite due to its steeper trails(更陡峭的小径). " They're more 7 than those of the other four mountains," she said. But instead of making her afraid, the challenge 8 her concentration(专注力)。
However, Zhen said the most daunting(令人生畏) like was climbing Taishan Mountain. It was due to the largest tourist rush she had ever seen. "We could only move up one step every five 9 or so, " she recalled.
Zhen decided to climb the five great mountains when she finished middle school. "I wanted something that would allow me to 10 see my growth and changes over time. As I grow older, I want something to share with others," she said.
