read: 牛津词典释义 [ V speech ] to have sth written on it; to be written in a particular way 写着；写成

The sign read ‘No admittance’. 告示牌上写着“禁止入内”。

I've changed the last paragraph. It now reads as follows... 我已经修改了最后一段。现在是这样写的…

say: 牛津词典释义[ no passive ] ( of sth that is written or can be seen 书面材料或可见的东西 ) to give particular information or instructions 提供信息；指示

The notice said ‘Keep Out’. 告示上写着“禁止入内”。

The book doesn't say where he was born. 书上没说他是在哪儿出生的。

The guidebook says to turn left. 旅游指南上说应向左拐。

请教专家：以上read和say这种用法是否相同？

例如，我想表达：这封信上写着这个学校很美。

The letter says this school is very beautiful.

也可以用reads，即The letter reads this school is very beautiful 吗？

如果可以，但为什么考试，学校试卷答案只能是says, 不能reads

 (考试是选择题：The letter (  ) this school is very beautiful.  A. says, B. reads C. looks, D.writes. 答案是A.says)

又如：一张纸上写着2句话。

A piece of paper says two sentences, 还是 reads呢？还是二者都可以呢？