document.write("<div class=\"prevBox\"><div class=\"prevBtn\"></div><p><a href=\"/story?sid=84388\">气候变化威胁全球植物物种</a></p></div>");document.write("<div class=\"nextBox\"><div class=\"nextBtn\"></div><p><a href=\"/story?sid=84390\">科学家破解烟草合成尼古丁之谜</a></p></div>");