【正确答案】 C

【答案解析】原文：American scientists say they have developed a way to grow wood material in a laboratory. The method could create different wood products indoors in a single process, greatly cutting the cost of production and reducing damage to the world’ s forests. Researchers from the Massachusetts Institute of Technology demonstrated a proof of concept by growing wood-like structures from cells taken from the leaves of a flowering plant. The results were recently reported in a study appearing in the Journal of Cleaner Production.题目问的是我们从这项新的研究中学到了什么。根据新闻可知，一项新的研究显示，全球鲨鱼的数量在过去50年里下降得多么严重。故答案为C。