【正确答案】 B

【答案解析】[注释] 本题题干中的control一词与原文are…in their hands是同义词，所以可以确定本题的依据句为：...but the results are not entirely in the sculptors’hands.“if it is extremely sunny and warm，”...，“we will erect old sail from sail boats into the air to block the sun from melting the sculptures．”If it snows，...，teams have to work extra hard to scrape(刮掉)the new snow off their work．其他选择项不能满足题干的因果关系。只有B项选择说明了两种可能性，能够体现与题干的因果关系。