To ealuate nicotine exposure more precisely, they measured study participants' blood leels of cotinine -- a marker for nicotine exposure. 為了精確評估尼古丁的危害程度，研究人員檢測了自愿者血液中的吡咯烷酮的含量，該物質(zhì)為尼古丁體內存在含量的標志。
Its distinctive markings--broad, white bands of fur alternating with black, and small black circles around the eyes--have endeared the giant panda to animal lovers everywhere. 它全身黑白色相間的寬條紋以及小小的黑眼圈，是它最明顯的標志，也因而受到各地動(dòng)物愛(ài)好者的喜愛(ài)。
