yī rì qiān lǐ 一日千里

成语 (Idiom)：一日千里 (A Thousand Mile A Day)

意思（Meaning)：

如骏马一般能一日行一千里，比喻进展很快。
Like a fine horse able to travel a thousand mile in a day,  metaphorical meaning is improvement at a tremendous pace.

例如（An example):

电脑领域里一日千里的进展, 为许多人带来了喜悦。
Using this idiom to describe the advancement of computer technology, has brought joys to many people.

典故(Classical Literature): 

《庄子·秋水》：“骐、骥、骅、骝，一日而驰千里。”《史记·刺客列传》：“臣闻骐骥盛壮之时，—日而驰千里；至其衰老；驾马先之。”

yī mǎ dāng xiān 一马当先

成语（Idiom）：一马当先

意思（Meaning)：

比喻领先，起带头作用。

Take the lead, be in the forefront.

例如（An example):

“一马当先“, 成为我的博客里的第一个成语！
This idiom is the first idiom used in my blog.

典故(Classical Literature): 

明·施耐庵《水浒传》第九十六回：“即便勒兵列阵，一马当先，驰下山来，犹如天崩地塌之势。”

qǔ gāo hè guǎ 曲高和寡

成语（Idiom）：曲高和寡

意思（Meaning)：

曲调高深，能跟着唱的人就少。旧指知音难得。现比喻言论或作品不通俗，能了解的人很少。
Literally，this idiom means music composed with high pitch, deep and complex content, can only play or sing along by few people. It is usually used to describe a piece of work which is outstanding and not simple, and only few people could appreciate or understand it.

例如（An example): 

交响乐曲，一般都曲高和寡，有一些音乐修养的听众才会起共鸣；普通听众多只是喜欢听乐曲优美的旋律，称赞交响乐高超的水准和为乐队精彩的表演喝采。
This idiom is used to describe high standard symphony music played by orchestra. Such music pieces required audiences with music background to fully appreciate the pieces. The general audience like the pleasant melody of the symphonies, will praise the brilliant standards and applause the wonderful shows performed by the orchestras.

典故(Classical Literature): 

战国·楚·宋玉《对楚王问》：“引商刻羽，杂以流徵，国中属而和者，不过数人而已。是其曲弥高，其和弥寡。”