The major productive methods of serin are albuminolysis, fermentation method, chemical method and enzymic method. 其生产方法主要有蛋白质水解法 、 发酵法 、 化学法和酶法,其中酶法是现在研究丝氨酸制备的重要方法.
负责选举的官员们已经临时安了几个喇叭，让投票者可以同时享受音乐。Election officials have rigged up speakers to provide voters with music.人们点燃烟花，按响汽车喇叭。People set off fireworks and tooted their car horns.骑车人危险地在车流中飞速穿行时，汽车喇叭的嘟嘟声响成一片。Car horns toot as cyc...