straight 是形容词、修饰名词、或做表语；
比如：
This pencil is straight.
He can draw a straight line without a ruler.
straightly 是副词、修饰形容词或动词；
比如：
This kid can walk straightly.
相关介绍
Straightly making use of analytical formula of single layer system combine that of multilayered system.
直接利用单层系统的解析解式组合多层系统。
By the website, enterprises can face to customers straightly to reduce their marketing cost.
通过网站，企业能直接面向消费者，减少营销成本。
The new album went straight to number one.
这张新的歌曲专辑一举登上了周销售量榜首。
