-----------------------------------
延々， 延延， 蜿蜒， 蜿蜿， えんえん
1. endlessly, continuously, (going) on and on
2. meandering, winding, sinuous, serpentine
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
