彻底刷牙有助于口气清新。A thorough brushing helps to freshen up your mouth.空气稀薄清新，其间日光蒙眬，寒气逼人。The air was thin and crisp, filled with hazy sunshine and frost.她的房子光线充足，空气流通，清新整洁。Her house is light and airy, crisp and clean....
A friendly critic might have called his heaviness weighty.善意的评论者甚至能把他的笨重举止说成是稳重沉着.Everything in her person was round and replete, though without those accumulations which suggest heaviness.她身上的一切都圆圆的,显得饱满, 然而并不给人以笨重的肥胖感觉...
Lignin is a characteristic component of secondary walls.木质素是次生壁成份的特征.A new syntan product prepared with tar phenol and lignin sulfonic acid.以工业副产物木素磺酸和焦油酚为主要原料研制出一种新的合成鞣剂.Alkali lignin is an abundant, cheap and renewable...