some essential method to write in markdown

first article。

first article。

first article。

first article

first article

####### six # is no title

-first article
-first article
first article
first article
first article

first first first first first first first first first first first first first first first
first first
first first
first first

first first first
two enters to quit this‘>’

library('tidyr')
detch('tidyr')
#they know what code i can write.

if u want center：:-----:
if u want right-aligned：-----:
left-aligened:-----

-----:just as a dic
--------:yet i'm longer

webs of markdown

收集了一些介绍markdown的网站，
1.简书:献给写作者的 Markdown 新手指南
2.简书：MarkDown使用教程