As we all known,the economy has witnessed rapid development

As we all known,the economy has witnessed rapid development in the past 30 years 语法错误
On the other hand,a laptop is so portable that draws people 's attention.有什么语法错误

As we all known, the economy has witnessed rapid development in the past 30 years 语法错误
答：修辞、逻辑错误（属于高级错误）.witness见证,不仅可以用“人”作主语,也可以用“年份”等等作主语,这是拟人用法如：1997 witnessed .
但见证的宾语应该是发生在别的事物上的事情,而这句话显然是想表达“在过去的30年里经济有了快速的发展.所以这个witness用词不当.应该为enjoyed较好.
Oh,不好意思,没有发现前面的As we all known这个低级错误.楼主不会是误打了吧.known明显是know之误打错误.
On the other hand, a laptop is so portable that draws people 's attention. 有什么语法错误
是的,先改一个低级错误：so+adj.+ that-结果状语从句,这个从句中没有主语it
这个高级错误就说不太清楚了.就是这个portable 便携的,可搬运的,一般就这么用就可以了,没有程度副词修饰它的必要.本题句本身造得不是很好.
再问： 谢谢您啦~~~~