1. (2019·全国卷Ⅲ) 阅读下面短文，从短文后各题所给的A、B、C和D四个选项中，选出可以填入空白处的最佳选项。

    The small town of Rjukan in Norway is situated between several mountains and does not get direct sunlight from late September to mid-March- 1 six months out of the year.

    "Of course, we 2 it when the sun is shining," says Karin Ro, who works for the town's tourism office. "We see the sky is 3, but down in the valley it's darker — it's like on a 4 day.”

    But that 5 when a system of high-tech 6 was introduced to reflect sunlight from neighboring peaks（山峰）into the valley below. Wednesday, residents（居民）of Rjukan 7 their very first ray of winter sunshine: A row of reflective boards on a nearby mountainside were put to 8. The mirrors are controlled by a computer that  9 them to turn along with the sun throughout the 10 and to close during windy weather. They reflect a concentrated beam（束）of light onto the town's central  11, creating an area of sunlight roughly 600 square meters. When the light 12, Rjukan residents gathered together.

    "People have been 13 there and standing there and taking 14 of each other," Ro says. "The town square was totally 15. I think almost all the people in the town were there. "The 3,500 residents cannot all 16 the sunshine at the same time. 17, the new light feels like more than enough for the town's 18 residents.

    "It's not very 19,” she says, "but it is enough when we are 20.”