11. He was in a over-shirt, and wearing cerulean close-fitting pants, beneath which was a pair of leather shoes, carefully polished before he went out.
12. Before playing the Guqin, he took a deep breath to let the mood calm and his facial expression was serene and solemn .
13. Most of us knew that "Cultivation of Ideological Morality" was a course of no importance even before we entered the university.
14. Before daybreak, a new study day begins; after 12 o'clock, the desk lamps are still glowing with a faint light.
15. Above all, what we heard and experienced before blocks us to find the truth.
16. It was already black before I finished my last class.
17. Before my admiration poured from my mind, my eyes caught one very essential point I deliberately neglected at first sight.
18. You need to wait for a long time sometimes because others were using the washroom before you.
19. They got up before day, and the school ended at 10p.
20. "\