-----------------------------------
一流， いちりゅう
1. first-class, first-rate, top-flight, top-ranking, leading, eminent, top
2. characteristic (of), peculiar (to), unique (to)
3. school (e.g. of flower arrangement)
4. one flag, one banner, one streamer
tbd
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题；表示与另一选项（无论是否明确提及）形成对比；表示强调
