参考：http://www.linuxidc.com/Linux/2015-10/123945.htm
where, which, when,等不但可以用在从句中， 而且可以用在 动词不定式中， 如： the path where to be write...
在/etc/httpd/conf/httpd.conf中， 默认设置的 总的 根路径
#
# Each directory to which Apache has access can be configured with respect
# to which services and features are allowed and/or disabled in that
# directory (and its subdirectories). 对一个目录的设置， 会同样的作用于他的子目录！！
#
# First, we configure the "default" to be a very restrictive set of
# features.
#
<Directory />
Options FollowSymLinks
AllowOverride None
Order deny,allow // 应该是先deny (all), 然后允许的明确指出
Deny from all // the default set is configured to be a very restrictive set!
</Directory>
#
# Note that from this point forward you must specifically（明确地） allow
# particular features to be enabled - so if something's not working as
# you might expect, make sure that you have specifically（要明确的指出、配置） enabled it
# below.
#
命令行管理mariadb ： 在第一次时候别忘了给你的root定个密码：mysqladmin -u root password '1234'
在centos7中， yum install mysql会自动的安装mariadb， 而不是mysql。
markdown的引用, 块引用, 就是用的 blockquote> 块引用...
aaaaaaa
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb // 如果不是在每一行前面加'>', 则可以只在段落的开始加> 符合.cccccccc
dddddddddd // 多级引用, 用多个>, >之间好像可以不用空格!??
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
