A、Locations. B、Investment. C、Weather. D、Equipments. C 文章中提到，雪上运动是一项受到天气影响的产业。因此天气应该是影响雪上运动的因素之一。故答案为C)。

Snow sport is a big business. Ski areas help support local economies. 165,000 people work in the mountain resort industry. It earns five billion dollars a year. (33) Snow sport, after all, is not just a business, but a business that depends on the weather.
    The ski season in the United States generally extends from late November until the middle of April. Last season, thirty-seven of the fifty states had operating ski areas. Nationally, close to five hundred ski areas were open for business. The industry recorded more than fifty-five million visits. (34) That was close to the average for the past ten seasons,but down six percent from the season before. The National Ski Areas Association said the main reason was the weather. The ski season was shortened in most of the United States because of warm temperatures and below-average snowfall.
    The largest ski resort in the United States is Vail,Colorado. The town of Vail and the nearby Vail Mountain make up the resort. The mountain is more than 3,500 meters high. A ski trip does not have to cost thousands of dollars. Many people go for a day or two and rent skis instead of buying them. (35) But people with enough money to stay at a nice resort might also have enough for some special things. Like riding to the top of the mountain in a helicopter instead of on a ski lift. And ski areas do not have to be outdoors or open only in winter. The first indoor ski dome in the United States is expected to open late this year in New Jersey.
33. Which is one important factor influencing snow sport business?
34. What is the amount of the visitors to snow sport resorts last year?
35. What do ski resorts provide for visitors of high consumption?