on the east,in the east,to the east,at the east之间有

网友回答

on the east 和.相邻的东部.
in the east 在.之内的东部.
to the east 在.之外（不紧密相邻）的东部.
======以下答案可供参考======
供参考答案1:
in the east of/on the east of/to the east of
这三个介词in on to主要用于表示方位：
in：在...范围之内;
on; 与......接壤,在......上;
to:与......相隔,(中间有一段距离);
Taiwan is in the southeast of China.
In the east of China is/lies Shanghai.
On the east of Shanghai is the East Sea.
Japan is/lies to the east of China.
Korea is to the northeast of China.
供参考答案2:
on 是与生俱来的！in 是包含，放进去的也可以的！to 是周围，紧贴的！at 是有距离的！
供参考答案3:
in the east 在.....之内的东部。
to the east 在.....之外（不紧密相邻）的东部。
on the east 和......相邻的东部。
1. in表示A地在B地范围之内。如：
Taiwan is in the southeast of China.
2. to表示A地在B地范围之外，即二者之间有距离间隔。如：
Japan lies to the east of China.
3. on表示A地与B地接壤、毗邻。如：
North Korea is on the east of China.